Welcome to our forum.
Perhaps you could open up the conversation with your boyfriend by bits and pieces? I can see why you'd have some concerns, if he's carrying around some baggage from a past relationship.
I think it'd be awesome if the three of you were to form into a triad. Something to be hopeful for, for the future?
I'm glad you're with us, in any case.
Love means never having to say, "Put down that meat cleaver!"