So take your logic and apply it to opposite sex relationships and people will will its the vaginal eroticism, its not about love most men cheat and most marriages end in divorce... its just about genitals and vaginal penetration by a penis.... see your own words and own logic turned around makes anything look bad through that lens. So is there a set of rules of where are acceptable places to put a penis? vagina yes, mouth depends, anus no... hands yes.... etc its just pretty childish