Must've been the other site where I faffed about this:

Austin Powers doesn't understand sexual preferences... sober. He fondly recalls a shindig where he shagged dudes, and also drank a martini from a shoe because all the glasses were in the sink. That doesn't mean he expects enlightened 90s types to keep footwear in the cupboard.

This retcon even fits his exasperation over Liberace - "but women loved him!" See chan-board bodybuilder culture, where dudes are free and women are an achievement. Especially for other women. He's perfectly cool with dudes fucking dudes, but has put precisely zero thought into why either dude would prefer that.