Mariah Carey and Nick Cannon are being sued by a former nanny who claims she was fired because she showed too much affection to their twins. Simonette DaCosta claims in a new lawsuit — obtained by TMZ — she was the full-time nanny when the kids were just infants. She fed, bathed and comforted them, but it didn’t sit well with Mariah. DaCosta claims the singer berated her for showing too much affection. Translation, it’s pretty clear she’s alleging Mariah was jealous because the kids liked their nanny way too much. DaCosta also claims she was worked too hard … putting in lots of OT — sometimes 100 hours a week. She wants back pay and other damages.