Relationship Disconnect 

If you're upset or at odds with your partner, sex is likely the last thing on your mind. There is a deep connection between emotional intimacy and sex. The brain is the largest sex organ; mental and emotional happiness is directly linked to physical arousal. 

If your sex problem is related to a communication issue, another relationship concern you've been sweeping under the rug or constant fighting, you'll need to clear the air if you expect both of you to lay down your arms and give your all to the lovemaking. 

Boredom 

Variety is the spice of life so it goes without saying that the bedroom blahs happen to nearly every couple. They usually begin to appear slowly simply because humans are creatures of habit that easily get stuck in a rut. Touch her here, tap her there, a little kiss here and she'll climax. When it starts to feel like a script or formula, you've got to take the initiative to stir things up before staleness turns to coldness.