Pretty much just:
> Two fifths of a gf is better than nogf.
> I live in the Bay Area, if I start insisting on monogamy people will think I'm secretly TradCath/NRx/watching Varg's videos.
> If I can't come up with a logical argument explaining why it's bad if my gf sleeps with other men then there's no reason for her not to sleep with other men. "It makes me feel bad" is not a good argument because I can just brainwash polyhack myself into no longer feeling bad about it. Knowing the evolutionary psychology derived reasons why jealousy exists just makes me more willing to be poly, since those reasons are not valid anymore, at least in my case. Claiming that it's bad/unwise/unworkable to go against the preferences set by thousands if not millions of years of evolution is to fall for the naturalistic fallacy.
> She's going to cheat anyway, at least like this I can maintain a little bit of dignity.