In order of preference
BDSM stories (M/f, either perspective but M perspective best)
Other erotica, heterosexual or bisexual ok but like some straight action in there
BDSM still images (M/f)
Artsy nudes for drawing practice, especially male nudes not erect
Fit chicks (inspirational)
Amateur couples where the guy is as hot as the lady
Some of the gay man stuff, particularly D/s or any power imbalance like that.
Ah. Yeah I am cold when sleeping, not sweaty. But that makes sense. We wash sheets on Fridays and they do not look dirty by then, not worried about being cleaner than that.