What do the two of you do to participate in romantic gestures? Men and women have very different ideas of what romance can be - women that aren't feeling "into it" won't really feel that you're being romantic if you're setting up a scene just to get it in. Avoid long-term relationship boredom by showing your appreciation (this works both ways) in big and small ways.

Do you talk to each other about important aspects of your day or serious issues in your relationship? Do you avoid working out long-standing fueds? Lack of communication can play a big part in a woman's interest in sexual activity. The relationship that breaks down in the living room eventually breaks down in the bedroom.

Do you have a date night? Don't let your relationship become a business arrangement. If you aren't doing anything fun together that you can laugh and have fun doing, well...there's that boredom thing again.

Lastly, the advice I would give to you is that if you truly feel tempted to cheat, avoid situations that leave you alone with the opposite sex if possible. Infidelity doesn't always begin as a sexual thing: don't discuss personal matters or become emotionally close to a woman that is not your SO. If you're unhappy enough in your relationship to need validation or sexual attention from someone new, end your relationship first and completely before becoming involved. Getting into a new relationship before you end the old one is the most emotionally draining situation you can place yourself in, especially just for some sex or excitement.

It takes 2 people to make a relationship work or fail. If you want to be with this woman, you can find a way. I learned the hard way that being right is less important than working out problems through communication and cooperation.

(I am a 31 yo divorced woman who ended her marriage of 8 years due to complete communication breakdown, boredom, and an insurmountable power struggle.)