If you're doing everything else right with regard to sex (e.g., the sex is good for her / she enjoys it /
orgasms hard and a lot), there's a simple way to deal with sexual refusal with any kind of live-in long-term female partner:
"Okay. Anyway, I'm going to head out for a bit."
You don't actually have to go hit on other women. Can just go sit in a café and work. And maybe check a few women's waists and hips out while you are there.
Gets most women back to the place where they are giving you all the sex you want again. It's 100% female competition... women want to shag the men other women want to shag. If she feels like other women don't want to shag you, she loses interest in shagging you. If she feels like other women are trying to shag you, she goes crazy trying to empty your balls into her so you're much less motivated to empty them into some other chick.
If she senses you are even beginning to reduce investment in the relationship, to reorient yourself to a fresh mate hunt, the threat of loss will motivate most women to open their pussies back up. Men want sex, women want commitment. As soon as sex goes off the table, your commitment starts to wane. She puts sex back on the table, your commitment rejuvenates.
Be sensitive to short-term, passing items, of course. A temporary health concern. Or she's had a really bad day. Or the two of you had a big fight.
If it goes on more than a week though (with health), or more than a few days (with something else), you need to start putting more other-woman pressure on the relationship again to get her motivated. There may occasionally be genuine long-term health issues (maybe she fails a pap smear and needs abnormal cells removed from her cervix and can't have sex for 3 weeks, for instance). But that's about it. "I'm depressed" is not an excuse, since if you do a good job in bed, penis-in-vagina sex with a desired partner is one of the biggest mood-boosters and depression-busters a woman can have. Careful about not going soft because "Well, she has an excuse. Maybe I should go easy on her." Beyond a few days, serious health issues are the only real excuse.
If her father died, she's still going to feel better getting reamed from behind by you 3 days after the funeral than she will if you let her lock herself in a room for 2 weeks and sob into a pillow, alone.
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Just keep in mind... sexless marriage = guy sucks in bed and/or there's no other-woman threat to the relationship.
Give her orgasms, and make sure she understands you can replace her anytime, and will happily commence your hunt if she refuses you too often or for too long. When her panties go up, your feelers for a woman who
will drop her panties for you go out. Watch how fast her panties drop when that happens. You do have to mean it though... a woman has to know you will actually cram your dick in another vagina if she deprives you too long or too often or you get too fed up with the sex from her.
This is how you get a healthy sexual relationship, where your woman is always willing to satisfy you sexually, no matter how far into the relationship you go, and enjoys herself immensely as she does it. The sex is good, and she knows you're with her because you choose her, not because you have no other choices.
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One other thing to be aware, at relationship commencement: mismatched sex drives are a huge looming problem.
If you have an enormous sex drive yet the girl has a low sex drive, you might be able to cajole her into most/all the sex you want at the beginning, during the honeymoon phase. But the longer the relationship proceeds, the more you will find yourself sexually frustrated, and her annoyed at your pestering. Likewise, if you have a low sex drive, while she has an enormous sexual appetite, the roles will be reversed. Try to find women whose sex drives closely match your own.
Chase