Maybe its just me, But from my experiences I think woman try to pretend they dont like it so the husband or boyfriend doesnt judge them. Or they get off to some one getting off on them with no concern for their pleasure. I dont know , just a theory.
She said in the end "He just spit on me", any man worth his salt would never let another man disrespect his wife that way, I can understand watching another man having sex with her and enjoying watching her, for all three to enjoy, but one still should show respect.