General Custer talks about "muscle spasms and Poison to the gonads" He describes this as "medical terminology". This may be too suggestive for younger viewers.
There is an implied same-sex character in the Indian tribe.
During most of the movie there is a strong sense of sexual tension/sex. It's presented in an almost funny way, but it's one of the key components of the movie.
Includes scenes in which sexual intercourse is strongly implied, with Little Big Man under the sheets with a giggling woman, in one case followed by two others in the same tent.
There is a scene where a married middle-aged woman bathes a teenage boy (he was fully able to do so himself) and kisses him after he gets out of the tub. Soon after this scene, Little Big Man hears/sees the same woman cheating on her husband with another man----the scene is not visually graphic however it is strongly sexual and lngthy---the two's legs are shown intertwined, lying in bed and we hear the two orgasm, explicitly.
Main character visits a "...house of ill-fame" where a worker describes herself as a "...fallen flower." She rolls off her stockings, unbuttons her bustier (only shows stomach), lays on bed waiting for customer (nothing sexual happens beyond that point).
An Indian woman gropes Little Big Man's sister's (clothed) breasts, to confirm whether she is male or female.
During a battle scene, a woman's clothes catch on fire, she takes them off and she is seen fully nude for a brief moment before falling into the snow. She is seen for a relatively far distance, so her breasts aren't really that easy to see. Nothing explicit about that scene.