Ok, I did some remembering and analyzing which I’ll spare everyone. If you can pull this off, this is what I’d suggest: You say he’s your best friend, so go talk to him alone, and relate to him as usual briefly so you’re in the usual friendly context. Then say something like, “Would you give me an honest answer about something?” If he says he agrees, ask something 2/3rds of what you want to know, like maybe, “Do you think I’m cute/pretty?” and see how he reacts. After all, it’s ok to ask your friend if he thinks you’re pretty and still be friends, but it’s an opening for him to show you interest if he has any. You can escalate the questions or step back from there as needed. Just hold yourself in the context and casual clarity that there’s nothing weird about talking to him and you want to find out what he thinks about you and if he’d like to venture that way or not, but it’s not a big deal and in any case you’re friends and there’s no reason not to talk openly and stay friends. If you can be not weird and worried about it, he probably won’t either, but if you are, he probably will be too.