Anata no Danna Uwaki shitemasu yo (あなたの勇者〈ダンナ〉浮気してますよ, lit. "Your Hero Has an Affair") is a manga series by Natsumegu Seijuu. It is serialized in Dengeki Daioh.
The manga focuses on a hero who is married, but monster girls seeking children of heroic lineage keep coming after him to steal him away. The hero's wife chooses to deal with the monster girls herself.