[Tadashi really considers Peter for a long minute or two, really thinking.

Water gets brought to them and he stirs his straw around slowly in the ice.]

I think. Until he shows back up, you just have to keep him in your thoughts. Do things for yourself, but that you wouldn't be disappointed to show him. And when - not if - he shows up, no matter if he remembers you or not, take it as a chance to get to know him again. It can't hurt to have a second chance, y'know?