Because you are not grossed out by these thoughts, it doesn't mean you actually like them. You will get recurring thoughts that you do not want of your friends. By concentrating on your groin, you will get responses from that area. You are doing a good thing by letting the thoughts be there. If you try to get rid of them it will make it worse. I had this type of OCD before and it was hard. But although I am not gay, I just accepted the possibility that one day it could happen. But I lived out my time enjoying men (I'm female), and still continue to do so. If you can, get therapy. Do not search for reassurance on here telling you you're not gay, because that will backfire. Only YOU have the power of your thoughts.