How can you tell if your best guy friend likes you but he already has a girlfriend?
You call him your best guy friend, but if you don't know whether he likes you or not, he's just a guy that you like a lot. If he already has a girlfriend, he likes her more than he likes you. That doesn't mean he doesn't like you. If you remain friends with him, and he doesn't remain such good friends with his girlfriend, he may decide that he wants you to be his girlfriend. Of course, by that time, you may already have another boyfriend who is better than he.
Should you hang out with your best friend and his girlfriend who you hate or should you not hang out with your friend?
Your best friend and his ex girlfriend have split up and both are free to date whomever they wish. You do not owe your best friend an explanation that you slept with his girlfriend. However, if you love her or are at least interested in her then it would be to your best interest to simply be honest with your friend and not mention already sleeping with her as that is your private information as…