AN: Here's another OPxRC M rated fanfic. Enjoy

In night-time, humans had returned to their homes. Autobots had to check themselves in sick bay and like expected, some dents here and there, few scratches. Some painkillers and a good night sleep should be enough for everyone.

Optimus just came from the shower from his bathroom, before he heard knocking on his door. He went to open it and find Arcee behind the door.

"I'm sorry to bother you, sir," she said, while looked away blushing to realize he just got from the shower, having nothing but a towel around him. "I-I just came to talk..."

"Okay," he said letting her enter to his quarters. She first stood there, since she wasn't sure if she would sit or not. After closing the door Optimus came to her. "What you wish to talk about?" he asked. She blushed a bit more since he was still wearing only a towel.

"I...I failed you, Optimus," she said and looked down.

"Failed me? On what?" he asked confusedly.

"On Elena," she said. Optimus was still bit confused. He moved to his berth and sat on it to listen well what she was talking.

"Arcee, what happened?" he asked. In this Arcee came front of him without looking at him.

"You asked me to look after Elena until you return, right?" she said.

"Yes," he said. "You asked me to promise that I will before you agreed to." why she is telling this could it be something to do with the Decepticon symbol on his armor. "Did something happened?" he asked.

Arcee started to tell him, about what happened after they defeated Unicron. How he didn't remember them and went with Megatron. How they were all worried, mostly her and Elena. How they tried to find him in many days. How Elena get herself into the warship. How they tried to get to Cybertron and there to Vector Sigma. All to the point where they got their him back.

Optimus was speechless. All that happened and all that pain it caused to the team. Especially to his little girl and especially to Arcee.

"I couldn't look after her," she said while tears started to appear in her optics. "I should have stopped her back then, but she just she knew that we needed to get to Cybertron. She wanted to make things less worried for us, but she caused more worries on me and SweetStar. I..."

She was cut off by Optimus who gave her one passionately kiss

"No, Arcee," he said. "You have no reason to be sorry. I let it happened. I should be the one ask to apologize."

"You did to protect us all," she said. "None of us didn't see it coming."

"You didn't either on Her," he said. "I know it was too dangerous, I don't blame you for it. You did best you could to look after her."

She only nodded quietly before she felt once more his lips on hers. Gosh, how she missed him kissing her. She never gets enough of it. Before it could get any heated, he broke the kiss.

"I guess I need to make it up all this to you." he said.

"Perhaps..." she said before he moved her to his berth.

She didn't need to say much since he started to kiss her again with passion and lust. Feeling his glossa sliding in her mouth to taste her. She started to kiss same way to taste him. It took while before he broke the kiss and moved bit up to give her some space, so she could remove her armor.

Once she was naked, he started to kiss her again. First kindly and sweetly, so, she could feel comfortable. Once it turned to intense she moved her hands to his cheek to get him closer to her. They keep making out for a while before he started to kiss her neck.

"Optimus..."

"hmm?"

"Do you remember anything, when you were..." she didn't continue. It probably wasn't the time ask such a thing. She wasn't sure would she even want to know what happened in the Warship. Optimus looked at her seeing that she was worried. He knew what she tried to ask.

"I don't remember..." he said, before made her look at him. "But no matter what had happened, it won't change anything. I still love you."

In this, he kissed her again passionately, in which she respond by kissing back. They kept making out for a while before Optimus moved a bit lower on her body still kissing her and she enjoyed the every bit of it.

When he came to her breastplates he stops there kissing and licking them. In this Arcee moved her hands to his head gasping and moaning in pleasure. The way he caresses her felt so wonderful. Like he knew how to please her and he did. He soon came back to her face and kissed her hungrily. during that kiss, he moved one of his hand between her legs, where he started to stroke her valve. Doing so, Arcee started to moan during their kissing and spread her legs wide.

He caressed her while before he moved himself down on her. He bent his head down to her port and insert his glossa inside. This caused her to gasp and made her hips move at him. It felt so good.

After such treatment, he came back to and kissed her again.

"I love you." she whispered.

"I love you too," he replies. "But we're not done yet."

"I know..." she said. "Go on..."

And he did.

Early in the morning, Optimus woke up finding Arcee next him. He couldn't help but admire how beautiful she look during her sleep. He just stood there watching her, before he caressed her face and gave a kiss on her helm. In this, she started woke up as well.

"Morning, sir." she said.

"Morning," he said giving warm smile. She just loved when he gave that smile.

"What you think she would say about us?" she asked.

"Hard to tell. How to react on our first Interface?" he asked.

"She took it pretty well," she said. Then something else came to her mind. "you think she will start to call me a mother?" Both starts chuckled on that idea.

"I think you should ask that from her." said Optimus before he started to kiss her passionately, which she respond in the same way.

"Dad, I Think we need to talk about..." heard a voice of Elena, who came out from her room and stood up right there, once she spots them. They both stopped making out, while Arcee tried to cover herself and Optimus got up. There was deep silence.

"Scrap..." said Arcee and put her hand on her face.

"Elena, don't you dare..." said Optimus.

"Okay,"she said blankly. "Excuse me..." she said before she went back to her and close the door. Then huge scream was heard from the door. It was hard to first what she was yelling, actually, it was just yelling.

Optimus look on Arcee.

"Took well?" he asked amusedly. She could help laugh a bit on that.

Most of the day Elena didn't do anything if not laying on the couch. Kids tried to ask what was wrong with her, but no one didn't answer. Others had a pretty good guess what was wrong with her, but they didn't tell the reason.