It's hard when you are used to a routine and then it gets broken. I.e. 7 nights a week you see your partner for 3mths straight and then they have to spend a week away in another State/Country. I get that, you're going to miss them and so will your children when you some day have them, it's especially hard for the young ones to understand but think of it this way, is he really working for enjoyment or to put bread (or M3's) on the table for you and to support a future? I am assuming he's well qualified or well thought of for any business to pay the time for him to travel, which usally means a nice salary.
I'm one of those guys and yes, it sucks a lot to be apart from my girlfriend when we're used to coming home (her place or mine) to one another every evening and then I have to go 2weeks without face to face contact but it's only the money I'm doing it for. We're planning to move in together (knock on wood) mid this year and im ploughing a huge amount of cash into savings so A) we can furnish the place, B) we have something to fall back on should circumstances change in the future whatever they may be, we're at least set up for this. A few weeks of the year is really no biggy in our eyes, not when we look at the bigger picture however, if it became a question of working away for month's then I'd have to reconsider my position...work to live, not live to work but it sounds like your other half is on the reasonable side right now.
I personally find that absence makes the heart grow fonder. All the tiny things she does for me that I get used to or take for granted are suddenly more apparent again and we maintain an very healthy relationship.