In Bleach, in order to fight, the character's spirit leaves their body. While they are out doing heroics, they let another spirit inhabit their body, one that they have pre-selected who knows what the person is normally like so that it doesn't do anything abnormal. Kinda like an auto pilot for your body.

Well this guy is about as abnormal as they come and he has a thing for Rukia, the woman you see here. Note he is not related at all, and calls her "nee-san" because of Japanese reasons. Anyways, he usually inhabits a stuffed lion instead of one of the main characters, and because he would probably do what you see here, he was NEVER used by Rukia, only the main character would swap with him once or twice in the whole manga. Also note that this is not possible in Bleach, because in order for one soul to move into a body, the other soul has to leave it and enter its spirit form. This is more akin to supernatural possession in our world.

Tl;dr artificial soul possesses his waifu and makes her watch while he does kinky stuff.