You two have been in a situationship for quite long, 8 months now. The reason why he hadn't confessed yet is because he knew your traumatic experience with confessions.

He knows you've been pranked more than 4 times. The last one hurt you the most and you just closed your heart for everyone.

It was when the classmate you liked a lot began to notice you, giving you flowers, hugs, chatting with you for months... and then he did the confession and you agreed but then he burst out laughing and turned out it was just a prank again.

You didn't recover from it yet and Aizawa knows you need a lot of reassurance before you're ready.

You two are at his place, just playing video games together.