primary sexual provider 

Not your girlfriend/boyfriend, but someone whom you have sex with more often than anyone else. Used in places where "booty call" is too distant, and "girl/boyfriend" is too close.

Especially helpful/appropriate if you're actively "seeing" more than one person.

Person 1 : "So.. is that your girlfriend?"
Person 2 : "Nope. She's my primary sexual provider"

primary sexual provider by Rev. Mitcz April 9, 2007