As long as he is being respectful and not putting his nose in your relationship with your gf then MYOB and stay out of theirs.
I can't stand people who want to micromanage other people's relationships.
40 yo straight female
Married in the eyes of the government to Butch since 2001...
Murf my monogamous second husband has been with me since May of 2012.
In a V relationship with an average 50/50 split of time between my two husbands.