I really wouldn't bind them. It's really not the best thing if you hope to have a healthy development and no one wants sagging issues. However, I understand how you feel and realize that it's a difficult position you're in. I'm still in boy mode myself, but I have very noticeable breasts and people do look at them. At this point, I've just embraced it and have gotten used to having boobs. Besides, everyone can tell something is going on in general despite being in boy mode. At a certain point, you really can't keep hiding. Sure, you can cover your boobs, but what about everything else? It's just something to consider because you've been on hormones for quite some time. Even if you can keep things covered for a little more, sooner or later it will come out. I'm not trying to scare you, but it's the reality of the situation. Nonetheless, I do hope you can find a way to cover things up long enough for everything to be okay for you. Just be aware that many people are on to us even when we think we're hiding.