Why doesn't my husband look the other way if I flirt with others?

A guy who marries a divorcee like me (or a widow) knows and accepts the fact that I was fu**ed by somebody else previously. He also very well knows and accepts that in case our marriage fails I would move on with my life and marry somebody else in future and gets fu**ed by him also. Then why does he expect me to be faithful to him while married to him? Why doesn't he look the other way if I flirt while married to him even though I don't take a single cent from a parasite like him and he lives in my home, uses my car and I pay for all his expenses?