As a teen, I never told my boyfriends about my abuse because I was protecting my parents' secret.

I think the other posters' suggestions are good.

I don't know how many details your boyfriend wants to know. Or how many detail you need to tell him. Only you can decide how much is appropriate to tell him.

Since abuse topics are serious conversations, maybe prepare him first. Let him know at such-n-such time you'd like to discuss some problems you have had with your mother.

Also, you could write stuff down as a guide for you or for things you want him to read because are unable to speak those words outloud.

Huggs are very therapeutic. Sometimes you can talk vaguely about stuff and still find healing through the huggs you receive.

Take care of you.