One of my guy friends keeps texting me, asking about me and my life, and is apparently curious about my boobs because he says he thinks they are a decent size and I guess he wants to see them, even though I wear tight sports bras and binders. His questions confuse me, but I am not uncomfortable. Not really sure what to do.
You seem to be very young, and he seems to be interested in feeling your boobs. Go ahead only if it would be OK for you and your social circle to live tomorrow with the knowledge that he felt them. In the case of my group of friends, girls wanted boys to feel their bodies when we were 13, we did everything in "public" (in group slumber parties, all naïve) and everyone was OK with it, zero bullying and haressing afterwards. If that's not the case, don't do it. You know which way it's gonna go.