It's such a hard thing what you are going through! I think you need to have the open discussion, find out how he feels sexually. Has he ever been with a man? You mentioned he loves you and he probably does, but if you stay with him you will always be wondering if he is still talking to men or organising things. The best thing to do right now is be strong, be honest and open it will hurt but just get it all out. Sorry I probably don't have much to say but I remember when I went through something very similar it was nice to just get a reply so that your not alone. Be strong!