"Cupboard love"

I was looking something else up in my much-used The Penguin English Dictionary, 2nd Edition, and noticed in passing a bit of vocabulary that could be useful, I think, especially when warning naive young people of the hazards of the big, wide world:

cupboard love noun insincere love professed in order to get something

For that matter, I can think of a few folks who could stand to be reminded that this is a bad thing.

For that matter, I could probably point out some people who apparently have never been told that there's anything wrong with playing people along.

Sigh.

P.S. Cupboard love is hard to say, or at least it strikes me as hard to deliver in such a way that a person who was unfamiliar with the phrase would understand without an explanation. Does anyone know of other words or phrases (suitable for polite company, I mean), that cover the same ground but aren't so vague to the ear?