Power: actor dominates another person sexually which reinforces the viewer's self-perception (vicariously through the dominant actor) as masculine whether or not they really live up to the ideal of a powerful, masculine man irl
Acceptance: actor is sexually desired despite falling short of the masculine ideal OR actor meets the masculine ideal and is desired because of that but does not dominate

"Pizza guy" trope - man is not traditionally in a role that is seen as successful or powerful. Gets sex despite their lower social standing because of their innate qualities (attractiveness) or just because they are desired by the pizza recipient
Femdom - actor is intentionally put in a role of submission but is still sexually gratified, if not also desired
Old/ugly guy with younger person trope - man is not traditionally attractive, but is still desired
Attractive guy with attractive person - man is desired bc they are hot, viewer also wants to be desired bc someone thinks they're hot
Incest - desired by someone they care about in a way that is strong enough to break the incest taboo. This may also be a power fantasy if the man is in a position that is typically seen as submissive (son, younger brother) but gets sexual power over a family member.