Some posters have talked about it being a good idea to get to the bottom of the reasons.
I dont agree.
Of course, I did myself spend years trying to do so. BUT firstly, you never will, if it is workaholism, and it probably is. They deny it to themselves, and there are years on end of this reason or that, and in the end even when h worked for himself finally and I could actually count the days (by looking at his day rate and multiplying), he got angry and defensive and had 'reasons' to present.
It took me far too long to see that the angle to take here is not a cat and mouse one about whether or not he has to. Anyone can see he doesnt haveto anyway. He may think he has to, which is an entirely different thing. Or he may like to, for any of a number of reasons.
The real issue is what the OP is expected to accept and why, and what she is willing to accept. It is about his respect for her and their belief in fairness, and it is also about her boundaries, or the erosion of them over time.
Oh, and I agree with the poster who raised the issue about some men at work. As an ex senior manager myself, I just saw heaps of men working late and hardly any women. Who got the promotions? We did, that's who, leaving alot of the men resentful.
I even remember nearly not taking my first project management job because I was so worried about the hours my PM bosses always seemed to do, when I had a small child myself and was a single parent. I didnt do those silly hours, though, and ended up managing most of them, much to their delight.