This type of girls are so cunning in their dealing, when they first starts a date with a potential costumer, they will give you frequent great sex(they are very good in bed) without requesting anything in return at least for a week or less. When she has succeeded in blowing off your mind in bed ( that period you starts behaving like a small pikin) ,then gradually she reduce the fun ( to make you beg for it) to a reluctant transactional chore she performs for you only when you have done something for her first (usually something of monetary value). Sex now becomes a reward in the relationship.
2. She makes it a routine to request for something (maybe monetary) before giving you sex: