how should i tell him?

Put plastic sheets on his bed.

 

I would tell him but when your discussing sex or about to get to it. Chances are that if you don't make it a big deal he won't either.

 

how could he even know if he`s inside you?
it`s not an issue

 

Don't tell him. I agree with one of the previous messages, act like it has never happened and he will think he is some kind of stud!!

 

Tell him. It's part of who you are. Why hide it? Why pretend otherwise. Honesty is everything, not to mention it's hardly some dirty, shameful secret. It's just something that happens.