Three or more girls/guys are giving intimate, but not overly sexual, affection to one person.
Criteria
The harem should be giving lots of attention to the lucky person, preferably by hugging and caressing him/her.
Sex (penetration, masturbation...) is forbidden. However, sexual suggestions are fine to some extent. (e.g. breasts or legs touching the lucky person as a result of the hugs, etc.) Nudity is okay if it is affectionate rather than sexual; usually it is not, so most people here wear clothes.