I'm bi 44 male from a ranch family in tx. This is me opinion. I think a couple things come into play here. #1 the bi guy grew up where it was forbidden but over the years the old super conservative peeps have passed on and everyone has come more accepting. #2 the guy is like me and just likes ass. Male or female, I can jerk off too any nice ass. But, I lean straight but I'm definitely bi. Other than ass , I'm way more sexually attracted to woman. ( I like bi couples), and feminine t girls too. But I think there comes a time where a bi guy just gets tired of all the b.s that woman can cause in a relationship.
Borders are set up front with guys. No bullshit. It is easier for sure! And for the record, look how excited I got just typing this. My chub is putting this g-string to work