This is a very common story actually, because Guy A didn’t make things clear, maybe even didn’t know what he wanted, kind of lame, a bit scared, etc. If you’re no longer into him (which would be to be expected, TBH) then pursue guy B who may well be clearer and more forward with you. You owe nothing to guy A, you have made no agreements with or commitments to him and if he feels bad about you going after guy B then that’s his problem because he didn’t make anything clear. (Hey, maybe he just sees you as a close friend anyway.) If you really do still like guy A a lot then it’s time to have a conversation with him, and yes it involves being very clear and asking what his intentions are. The worst thing that could happen is he no longer is interested in you at all, but don’t be scared of that possibility, you still have people like guy B that you know.