Relationships are transactional. Some people do a better of job of communicating with their partner what the transaction is than others, but most of them have different parameters. Some relationships exist for the sole purpose of the two partners having sex and pleasing each other that way. And as long as both of them are aware of that, and they don't have other needs that the other person doesn't know about, then that's fine. Another relationship might exist solely for the purpose of companionship; a couple might just want someone to see a movie with each week, or someone to discuss books with twice a week over coffee. Everything in between is possible too.

So the answer to the question, "How important is sex in a relationship?" is most easily answered with, "It depends on the relationship."

Problems start to arise when people need something from a relationship that they can't get. Suppose you're into a certain bedroom activity, and you marry a woman who hates that particular bedroom activity. She refuses to do it, ever. Are you willing to live the rest of your life without it? Or are you okay with getting that need met elsewhere? Is she okay with you getting that need met elsewhere? Or is it something you're willing to give up in exchange for the other perks you get out of the relationship?

If sex in a relationship with a wife is a 10 on a scale from 1 to 10 for me, and 1 on a scale of 1 to 10 for her, then we might have a troubled marriage. In fact, it's almost guaranteed.

There's nothing wrong with wanting certain things in a relationship sexually. But it's important to figure out what's important for you and whether or not your significant other is a good fit. And that doesn't just apply to sexual things; it also applies to things like conversation, kids, housework, etc. It's completely acceptable for a man to expect his wife to do housework, but she needs to be okay with expectation too, or their marriage is going to be troubled.

Sex is no different. It's all about communicating your needs, finding out your partner's needs, and making sure that a relationship is a good fit.