Cupboard love
Definition 1 of 1
Pro Tip 1/3Underlying Motive
Cupboard love indicates a deceptive affection to gain favors or material goods. 
She lavished him with attention, but it was just cupboard love for his inheritance.
Pro Tip 2/3Not Genuine
The affection is temporary and not from the heart; it disappears once the goal is reached. 
He's so sweet to me when he needs a ride, a classic case of cupboard love.
Pro Tip 3/3Common Usage
It's typically used for humorous or critical commentary on someone's conspicuously strategic affection. 
My cat only comes to me for cuddles when she hears the food tin, total cupboard love!