Not Cuck per se, but close enough. I have been in a bi threesome and a bi foursome with my ex and a friend . Our girlfiends decided "we're not going to eat each other unless you do it too". "When we come back you better be doing it". After they came back and we were doing it they said "we didn't think you would do it". Long ago, but that's how my half-bi-ness started. And truth, they were fun to watch later. Moral of this story: Be careful when chicks go to the bathroom.