Please your man in the bedroom
When a woman realizes that she is no longer able to keep his man's attention focused on her, what does she do? Her first suspicion is that he is having an affair, which may very well be true, but often it is not. As several years have passed and she has stopped taking care of those little things that she used to do when she first met him, interest wanes, and the relationship becomes dull.
It doesn't have to. It also does not take enormous effort either. And hardly any investment required. Here are a few useful resources:
LuvCube article on How to please your man in the bedroom
Tim Rassiter on How to drive your man wild?
500 Lovemaking tips and secrets