Generally, the more you meet someone of the opposite sex's emotional needs, the more they like you. Eventually when you have made enough deposits to their emotional needs account they start falling in love with you. It is a natural reaction that we are all wired for. (This is why opposite sex friendships are so dangerous in marriages.).
However, you can make withdrawals from that account as well, with anger outbursts, selfish demands, etc. etc. Often withdrawals are in much larger currency than deposits, so, for example, an anger outburst withdraws far more than a warm hug deposits.
A Christian psychologist has studied 10,000's of couples and reduced his observations to a simple pattern found in blissfully happy marriages by those who followed it (about 20%) and at a minimum, unhappy marriages, but often also affairs and divorces for those who didn't. Once he realized what the pattern was, he began very successfully coaching couples to follow it.
He has never seen a failure in a marriage where both spouses follow the pattern of making deposits and avoiding withdrawals as long as they protected their marriages from opposite sex friendships.
He gives detailed information about his observations and a plan on how he has seen this be implemented in the successful marriages that you can apply to your marriage, for free on the internet.
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He also provides one on one support for free during a daily radio show where he often spends a full half hour on each couple. This radio show is posted every day, also for free (and without commercials), on their web site and provides a lot of insight on practical application since putting it to practice can be more difficult than it sounds, so I'd encourage you to listen to his show every day.
When a woman is deeply in love with her husband, she tends to want sex nearly as much as he does, when sex is an event that expresses a deeply felt, emotional loving bond in a special and precious friendship as only possible between husband and wife.