mode swings

my girlfriend and i have been together for three years the first year was great in the bedroom but now she says she is not in the mood and when she is it only happens like every two to three weeks what can i do to put her in the mode more often ?

You're girlfriend's drop in her sex drive could be due to a variety of reasons stemming from either prescribed medication, stress, or just issues in your relationship. Ask yourself if everything is okay in your relationship before trying to seduce and please her again. Also, after so long, partners usually don't feel the need to pounce on each other all the time as if it were the last time. In the beginning it's normal to because you don't know how long you will be with the person and because it's so new. Try to go back to what brought you two together in the first place again and act on it. What did you both enjoy doing during your first year together that the sex was so good? It can be as simple as acting out one of your first dates, to reminding her why you're in love with her and so on and that can not only stimulate her memory but get her aroused. You may also want to consider trying out something completely new to create new memories and spice up your sex life. Either way she should want to have sex with you more often. Start brainstorming and best wishes!