I am sure this has been done to death over the years, and I'm also aware that this isn't a big problem in the wider scheme of things, but I'm struggling to work out how to deal with this.
About two years into our marriage, DH took up golf and it turns out, he's really quite good at it. Clearly he's not going to be a professional, but he's coming in the top ten at tournaments etc, and he loves it - it gives him fulfilment and pride.
He tends to be away for the weekend on average once a month, plus away for a whole morning 2 further mornings a month, plus the associated practice. To be absolutely fair to him, he's very good at balancing practice around family life, but obviously matches can't be moved. He's also good at letting me have time for my hobbies, but only if I have something actually scheduled in - if I want a morning off to go shopping, that doesn't count!
What I struggle with is the conflict between wanting him to be happy, and enjoy life, and the desire that I have which is to enjoy time together as a family - even if its just mooching around at home. So when he asks me if I "mind" him going off to such and such tournament at the other end of the country, I feel that it would be wrong for me to stop him, but then I resent him for going so can't give him my "blessing" to go.
I worry that our social life suffers, as its almost impossible to have friends over (or I feel rude inviting friends for the weekend if I know he's going to disappear off for half of it) or to accept invitations to go away. I find it hard work being at home on my own, and get quite lonely when he's away. I also struggle to accept the associated obsession - the only thing he really gets animated talking about is golf, he gets into frightful moods if its going badly, he spends hours reading about it online.
We have one DC and another on the way. Any suggestions? I love him very much, he's kind and a wonderful father and husband in so many respects, but I'm terrified of becoming a golfing widow and resenting him for it. There are days when I feel like our marriage won't survive, which seems such a petty reason 
Sorry, this is a bit long!