Cupboard love
"Cupboard love" is an English expression referring to affection that is given purely to gain a reward.
The term derives from the way in which a cat will give the person who feeds it superficial "love" (which is not normally exhibited) when it wants to be fed.[citation needed] The phrase is most often applied to human activity, for example when a child will say "I love you so much" before or after requesting a treat, for example an ice cream. Cupboard love is a milder version of conditional love, where love is given solely in response to certain behaviour.
Example in Literature: From page 47 of the children's book Miss Hickory by Carolyn Sherwin Bailey, copyright 1946: "Cow had been gone from the barn all day, and Mr. T. Willard-Brown [a tomcat] was anxious about her. Not on Cow's account. Oh, no! He had only cupboard love for Cow and had missed his daily saucer of warm milk."