[Oikawa avoids eye contact. He likes Yamaguchi, and it's not like he'll be happy when Yamaguchi realises he's not a good person but he's not going to pretend it won't happen. Because he's completely convinced that it will.]

And who's to say the situation won't change again?

I'm letting you have an out, Yama-chan. The least you can do is remember I gave it to you when you change your mind.