I'm homosexual and my boyfriend and i tried anal and now it's hard for me to poop.will it give me something or hurt me if i cant get the cum out.

Check: If persistant would see doc. Retention of ejaculate should not be harmful.

That depends: If he had any STI's what's done is done. Try to use condoms as they help prevent sti's. Eventually, the anus and rectal area should heal and the poop will come.

No condom?: Your high risk behavior puts you in contact with a variety of bodily fluids. Take extra precautions please! If you don't trust the contact individual in question, then DON'T take a chance! If you think you've been exposed to STD or HIV, get tested NOW & start treatment if positive. And, please be responsible not to put others at risk if you may even remotely have chanced an infection.