Happily married here,

but me too.....guys and guys, girls and guys, girls and girls.

When it comes to threesomes....I think it's important to all be on the same page. Have some rules that you and your boyfriend and the other woman agree upon...for example if you don't want your boyfriend to...well....penetrate the other woman, then make that clear. And respect her boundaries, too.
Enjoy.

Umm P.S. what happens in your bedroom is your own business, not your families....In fact best not think of them at all