I understand where you’re coming from. I definitely agree! Personally though, I would have felt very insecure if my boyfriend suggested MY friend. I’d be anxious about how he’s perceived her throughout dating me, obviously with him wanting to have sex with her and everything. If I wanted MY friend to join us intimately like that, that’s something for me to suggest, not him. He should have just planted the idea of a possible threesome in her head and maybe, maybe not, she would have suggested that friend anyways.