The Cuckold or the Bull

So there has been an interesting twist to the recent couple that I have somewhat converted. Last night, for the first time I went to there home, because she wanted him to watch or threesome. This was weird because the husband doesn't even look at me or say "hi," and suddenly it was going to be an all out happy fun time for all. I didn't think so, but she was determined and insisted that he wanted her pleased.
Well, we got back, and they proceeded to have sex in front of me, and I could tell he was fucking harder and better than he ever had before as if to prove something. At the end, she wanted me to spend the night in the guest-room, but I got a cab and went home, instead.
Another weird thing is I can't help but to notice that she is encouraging him to find other women but wants me to cut the other women out of my life, so am I the cuckold or the bull in this relationship?
Eh, oh well, I have a date with another girlfriend tonight!