My friend got engaged to a guy who he told me he was only continuing to see because it made the guy that he really wanted pay him more attention.

I'll try to keep this short and sweet.Set my alleged BFF up with a really nice, but emotionally needy guy I knew. They had their first date in early March.My friend (33) told me on the phone a month later that he was only continuing to see this guy because it made the guy who he'd been lusting after for well over a year pay him more attention than he had so far. That the guy I set him up with was too old (49) and he was turned off that the guy had a son only three years our junior. He also named several nit-picky things about the guy that he found incompatible. But he did like that the guy made repairs to his house.I sort of distanced myself from my friend following that and Have only spoken to him twice since the incident. The guy I set him up with proposed last week and he accepted with a wedding scheduled for Mid July.I cannot bring myself to RSVP in the affirmative for this and other reasons largely known to my supposed best friend.I know it would be wrong to tell emotionally needy guy what my friend was up to in the beginning. but now I feel that I've committed the worst possible mistake with him by setting him up with someone who he plans to marry who did not find him attractive and was using him for his handyman skills. My friend has never been able to maintain monogamy despite saying that he wants to and emotionally needy guy views sex outside of a relationship in a way that closely mimics the thought pattern of a stereotypical straight woman.Essentially I set someone up to suffer heartbreak.