clit nursing
When a character feeds from a clitoris in a manner similar to nursing from a mammary, either knowingly, be it by taste for vaginal_fluids or lack of nutrition alternatives, or unknowingly by mistaking it for a teat.
Often (though not always) associated with mother_and_son/mother_and_daughter incest and toddler/baby.
Not to be confused with any cunnilingus. The sucker is only trying to milk the giver's genitals, regardless of pleasure.