This one takes place a few weeks into the new school year, 4ish months after they tell Max that Sheldon is his dad.
Max ran to the door and opened it when he heard Sheldon's signature knocking. "Sheldon!" He exclaimed as Sheldon entered the apartment. "We're having career day at my school next week and my teacher asked if anyone's parents could come in to talk to my class. Do you want to come to my school?"
"Wow, that's a lot of information," remarked Sheldon as he set down his bag and took off his jacket. "Why don't we talk about it during dinner? How was school, aside from the career day thing?"
"Good. I got a hundred on my math test today. We're starting spelling words every week. It's a list of ten words we have to learn and on Friday we take a test to see if we know how to spell them. This week's words are super easy, so I think I'll get a hundred on that, too," the seven-year-old shared while Amy directed him to set the table for dinner.
Amy set dinner on the table, while Sheldon asked about career day, "What exactly would I have to do for your career day at school?"
"Everyone's parents come in and tell us about what they do at work. Mom brought a model of the brain last year and told us about working with monkeys. You can tell us about when you went to the North Pole before I knew you," suggested the second-grader between bites of food.
"Okay. I'll do it. This will be the first time I coming to something at your school. I'm excited to meet your teacher and classmates. Do you want me to talk about anything besides the North Pole?"
Remembering how it went when Sheldon spoke to the students at Howard's old middle school, Amy jumped into the conversation, "When you're deciding what to talk about, keep in mind you'll be talking to second graders. They're just starting to add and subtract double digits, don't go crazy with high-level, in-depth explanations. The simpler, the better. Besides, you only be talking for less than ten minutes."
After putting Max to bed, Amy and Sheldon were having tea before Sheldon went home. "I know I told Max I'm excited about going to his school, but I'm quite nervous about it."
"It will be fine," Amy smiled, trying to help Sheldon relax. "I can go if that would help. I'll sit in the back of the classroom with the other parents, but can jump in if you need me to."
"Max has been going to school with these kids for a few years. Will he tell them who I am or will he just call me Sheldon? Will the kids want to know why I'm there? He still calls me Sheldon. How will we explain to his class that I'm his dad, but he doesn't call me dad?"
Amy set her hand on Sheldon's. "I've explained our situation to his teacher. One of their first topics in social studies was different types of families, so they know not every family looks the same. I can ask Max if he wants his class to know you're his dad or if we should just say you're my boyfriend. The students usually introduce the person they invited, so we can let Max introduce you whatever way he's comfortable."
A week later, Sheldon followed Amy through the hallway of Max's school, along with several other adults also there for career day. They waited in the hallway until the teacher called the group in, where they stood along the back wall. One by one, the teacher invited each student to introduce their guest before the adult talked about their work for a few minutes. Finally, it was Max's turned and he ran to the front of the classroom as Sheldon walked around the desks to join him.
"This is Sheldon. I found out over the summer that he's my dad," Max proudly shared with his class. "Sheldon is a physicist at Cal Tech. I don't know what exactly he does, but he has a lot of whiteboards that he does really hard math on."
Sheldon smiled as the boy took his seat again. "Thank you, Max. I am a theoretical physicist at Cal Tech. Physics explains how everything in the entire universe works. Like Max said, I do a lot of really hard math. Do ever have a math problem that takes you a long time to solve?" Sheldon asked as many of the students nodded their heads. "There are problems that have been being worked on for years. Some people have gone their entire careers working on the same problem. There are different kinds of physics, though. My roommate Leonard is an experimental physicist, so he works with lasers a lot. Our friend Raj is an astrophysicist, so he spends a lot of time looking at the stars and data collected from telescopes." Sheldon noticed the teacher was signaling him to begin wrapping up. "I've only got a few minutes left. Does anyone have any questions?"
A few kids raised their hands and Sheldon pointed at a girl in the front of the room, "What's the longest you've ever worked on the same math problem?"
"I've been working on string theory since I finished my PhD, so about twenty years. Some progress has been made, but it's still years away from being solved. Any other questions?"
The boy sitting next to Max raised his hand and asked, "Why does Max call you Sheldon and not dad? Isn't that weird that he doesn't call you dad?"
"Okay, I think that wraps up Dr. Cooper's time," the teacher quickly interrupted and turned to another student. "Jessica, would you like to introduce who you invited today?"
Max looked at the boy to his left and stated, "I can call him dad if I want to, but I still call him Sheldon because I didn't know he's my dad until the end of last school year. Before that, I only knew he was my mom's boyfriend since I was little. I went my whole life not having a dad and now I do. I don't have to call him dad, but that doesn't mean he's not my dad."
The adults stayed through the end of the school day. Walking to Amy's car, Sheldon spoke, "Do you want to stop for ice cream on the way home? My treat?"
"Can we, mom? Please?" pleaded Max.
"Sure," Amy agreed as she unlocked the car.
The trio found an ice cream shop and made their selections before Sheldon said anything again, "I'm proud of you, Max."
"Thanks, Sheldon. And thanks for talking to my class. I know you don't like talking in front of a lot of people," the boy replied.
"You didn't have to answer that boy when he asked why you don't call me dad. I don't want you to start calling me dad until you're ready, not because some kid at school is bugging you about it. I'm okay if it takes years for you to call me dad. What you call me doesn't change anything, you know that right?" Sheldon asked, smiling when Max responded with an eager nod of his head while continuing to lick his ice cream cone.
Amy watched the two for a few minutes while enjoying her ice cream. "I'm proud of both of you for how today went. I don't know how I got so lucky to have the two of you in my life."