A proverb about it's a sin not to take what's you catch

Question

I may have dreamed this but I remember my Japanese teacher telling our class (23yr ago) about a Japanese proverb that went something like:

It's sin not to take the fish you catch

The teacher explained this to mean, men use this proverb to justify cheating. That it means, if a woman offers herself it's a sin not to accept.

What is this proverb?

Answer 1

The closest phrase in Japanese would be 据え膳食わぬは男の恥, but it says nothing about fish. The literal meaning of this phrase is "Not eating the meal set before him is a man's shame".