If you have strong feelings for this new man, but the threesome aspect of being with him and his wife makes you uncomfortable, then why not *just* be with him? Do they consider themselves a package deal?
Check out the essays here, especially the ones listed under the header Poly Configurations along the righthand side of the page:
The major players. Me, 30ish bi female. Gia, girlfriend of 4+ years. Clay, boyfriend/dom. Davis, ex/friend/"it's complicated." Eddie, roommate & fwb.
The supporting cast. Eric, Gia's husband. Bee, Gia and Eric's toddler. Dexter, Gia's lover. Helen, Eric's lover. Izzy and Nikki, Clay's partners. Liam, Eddie's husband.