Its really weird to me that after sex I always bleed, and its only with one partner, the other partners I have had it has never ever happened. Its weird to me. What do I do?

It sounds like he's either too rough, you're not well lubricated, or he's too well endowed. It could also be a medical issue.

Do you feel pain during sex?

Have you seen your doctor?

Having this checked out would be a good idea.