Disclaimer: I don't own Harry Potter.
On March 26,1988 Lily decided to surprise the kids and Sirius by bringing James home from the Sunrise nursing home in Godric's Hollow for a couple of hours in order to celebrate James's birthday which was on the 30th. Lily had confided her plans to Remus, Molly and Severus, since she had instructed Remus to pick up the food for the little party, Molly to bake a cake for the occasion and to set up at Lily's house, and Severus to help her in bringing James home for a couple of hours. She did instruct Sirius to take the day off since she told him about planning a party for James's birthday but not where the party was going to be. When Remus arrived that Saturday late morning, he planned on taking the kids with him to the park to spend a couple of hours there giving Severus and Lily a chance to pick up James from the nursing home before he had to pick up the food for the little party. When Severus arrived at Lily's he found her at the front making the entrance to her home wheelchair accessible for James.
"Hi, I wasn't expecting you until later, but now that you're here you can set up the backyard for James's party later on today. You don't have to worry about the kids getting in the way today, since they're out with Remus and Sirius will be over later. I'll make sure that he won't make any trouble for you, since you're my friend and I really appreciate you doing this for James," Lily instructed him while pointing him towards the backyard while giving him a smile that encouraged him.
An hour later Lily went out back to see what Severus had done with the backyard and to make sure that everything was perfect for James's homecoming. After looking and seeing what Severus did to the backyard, Lily came up to him and kissed him on the cheek. He was surprised at the sudden show of affection that she had shown him and he grabbed her waist and embraced her in a passionate kiss that lasted a couple of minutes before Lily pulled away from him and ran off into the house embarrassed at what she had just done, since she was still a married woman.. Severus was shocked at how he had returned Lily's kiss and how she had reacted afterwards. He complatated if she wanted to take their relationship further, even though she was still married and couldn't marry him until James died. Later on back the house, Lily thought about what she and Severus had just done and her growing feelings for Severus. She still loved James, but because of his condition it was like having another child. She could never divorce him, no matter how stubborn he was seven years ago, since he was the kids' father and she knew according to British wizarding law, that she could divorce James but she couldn't remarry until James's death. Besides, she still loved James though only as one of her children, since his attack and she couldn't bear the thought to divorce him no matter how stubborn he was seven years ago. Though Lily couldn't get the way that she felt when Severus held her earlier.
Later on in the car when they were going to the nursing home to pick up James, Severus asked Lily, "Why did you want me to come along, you know how much I don't like Potter? Is this your way of getting us to make up?"
"You've been such a good friend to me and right now I'm going to need a friend to help me get through this," Lily answered him honestly.
"I still don't understand why you want me to help out with Potter's birthday party for you, but I'll go since you asked me," Severus replied enjoying the fact that he was going to spend some time with Lily, though her husband and his friends were going to be there too.
When the two of them arrived at the nursing home, Lily immediately went to the front desk to let them know that she was there to check out her husband for the day. While Lily was working on the paperwork that would allow her to check out James for a couple of hours, Severus looked around the home and noticed that the majority of the residents were old enough to be James's parents and that the home seemed to be much nicer than the Janus Thickey ward of St. Mungo's. When Lily came back with James sitting in a wheelchair, she brought the car around, which she had magically added a ramp to it to make it easier to transport James, without getting him out of his chair. Severus was amazed at the changes in James since he had last seen him. He was now more alert and sitting up in a wheelchair, instead of lying in bed all day with no life in his eyes. He wondered how James would react if he knew about him and Lily kissing before coming over here, but before he could think too much about it Lily entered the car in the seat next to him.
Meanwhile after Sirius got done with his shift with the Auror office, he went straight to Sunrise where James was currently living, since he thought that James's party would be held there not realizing that the residents could take a leave of absence from the facility. When he got there, he was surprised to learn that James wasn't there, but was checked out earlier that day. After he went outside, he wondered who would let James out in his condition and if Lily knew about it. He went straight to Lily's house while waiting outside for her to answer the door he wondered how he was going to break the news that James was gone.
When Lily answered the door, he asked her, "Did you know that James isn't in the nursing home, and they wouldn't tell me where he is?"
Lily looked surprised at Sirius's question but then quickly recovered and answered him, "Oh I forgot to tell you that Severus and I picked him up earlier today so he's out in the backyard with the kids and Severus right now." Sirius looked relieved that James was here with Lily, but surprised that Snape would agree to help her pick him up.
Lily immediately ushered Sirius out back, where James was in order to try to separate him and Snape for the time being, plus she knew that Sirius was eager to see James and to make sure that he was all right. When Sirius saw James he was amazed at the changes that were made in a short period of time. He went over to James who was sitting in his wheelchair, looking more alert than Sirius had seen him in a long time. Sirius was also amazed at the board that James held in his lap that had different drawings on it to represent different possible needs that James could have, like hunger or thirst. "That board is just a start for James. He's now working with a communications therapist, so hopefully by Christmas he'll have one with the alphabet on it," Lily told him after she noticed Sirius looking at the board with interest.
A few minutes later Remus came in with the kids and the food for the party. The kids were excited about getting to eat pizza, cake and ice cream while Remus was glad that James at least would be able to spend one day at home with Lily, the kids and his friends. The kids immediately wanted to know when they could eat and Lily told them that it would be in a few minutes after she got everything set up. As soon as they saw their father, they came running outside to him while Lily finished setting things up for their small party. A few minutes later the four adults and the two children joined James in the backyard eating their lunch of pizza, while Lily was assisting James in eating. None of the kids noticed this, but the adults did noting the changes that they've already seen in him over the past couple of months. After lunch it was time for James to get his gifts that Lily helped him in opening them. Though he couldn't express his feelings over his gifts, he showed his feeling of happiness in his eyes. Lily then put his presents in a pile, so that he could take them back to the home with him. After the presents were opened, Lily went back into the house and returned with the birthday cake with Remus following behind her with the ice cream. After everyone, including James had their fill of ice cream and cake, Harry and Jamie wanted to know if they could go over to the Weasleys to play with their friends. Lily let them go after they gave their father a kiss on the cheek and were accompanied by Remus. A few minutes later only Sirius, Lily and James remained there, but James immediately fell asleep in his wheelchair worn out by that day's activities. Lily immediately wheeled him back inside, so that he could take his nap in the house. As soon as she got him inside, she immediately led him to the living room, so that when he woke up he would be in a more familiar setting. While James was having his afternoon nap, Sirius left to go home to get ready for a hot date later that night, leaving Lily and Severus alone for the time being. Lily then used a heating charm to heat up a couple slices of pizza for her to eat since she didn't get a chance to earlier, while Severus joined her. Well, James will be going back to the home in a few hours, though it was nice to have him home for his birthday even though he couldn't stay for long. "Don't tell anyone this Sev, but I am thinking about James staying with us for a week over Christmas if Sunrise will let him take a leave of absence from them for a week," Lily confessed to Severus while he looked at her amazed at how she was going to deal with James being at home with her and the kids for a whole week. Severus was amazed that she would even think about having James home for Christmas since it seemed to be tiring to take care of James and the kids on top of going to work every day.
A couple of hours later James woke up from his nap and so Lily with Severus's help, put James in the car in order to take him back to the home. Severus hoped to have some private time alone with Lily after James was settled back in the nursing home. After James was settled in Sunrise, Lily drove Severus to a secluded spot so that they could talk in private, without the fear of any interruptions.