klepto-snatch

n. a seemingly straight woman who makes a habit of stealing lesbian girlfriends of other lesbians, either for recurring hook-ups or one night stands
v. to steal (as a straight woman) a lesbian partner/girlfriend of another lesbian

Brenda says she loves her husband and kids, but she's a total klepto-snatch when she heads out to My Sister's Room.
That Brenda may be all smiles at the charter school board meeting, but if she tries to klepto-snatch Clarisse again I'm going to slap-jack that trick, Philly-style.