I'm straight but I just don't get excited about hetero situations in any medium :/ it's not to do with the people depicted, either; I think female bodies and make bodies can both be very sexy. I'm just fundamentally not turned on by male-female scenarios. Not grossed out or repulsed, it's just kind of "oh, okay, that is happening.". I could go on about why that is, but then we'd be straying into the specific preferences of mini's minibits, and the world isn't ready.
TLDR: straight female mini loves her some gay lovin'