I always prefer seat and lid down (animals), and I'm lesbian. In a multiple gender house, it seems to be..just don't whine about it. Although... almost falling into a toilet at 2 in the morning... is quite annoying... and gross. Safe reason = In of diarrhea just lafve the seat down. I have a couple/2 friends. He has a nervous stomach and have like 8 cats and a dog... lid and seat is always down. It's a male/female couple too.
I have a third suggestion that would also satisfy everyone, especially for these with a larger bathroom. Instead of having a bidet installed next to the toilet, a devise that no one really uses anyway, install a urinal. This will not only avoid any conflict but will also be a great conversation piece every time you have friends over.