Would you humor me and describe a typical day in your life together?
First of all, I have never quoted myself before. It feels narcissistic.
Secondly, there is a reason I asked about your typical day.
Personally, I believe when most people are having trouble in bed, the problem actually comes from another part of their lives.
This doesn't mean you are feuding with each other, necessarily, but that could be one explanation.
I was thinking more along the lines of boredom, in your case.
Routine is part of everyone's life, but if you are not careful, it can be deadly to passion.
For example, if you get up every morning, have breakfast, go to work for 8 or 9 hours, come home and make dinner and eat it in front of the television, where you vegetate until bedtime at 11, with very little genuine intimacy between you, why would your sex drive suddenly kick in when you go to bed? The best sex start long before the bedroom. There needs to be time where just the two of you are focused on each other with tenderness, playfulness and interest. When sex becomes mechanical, like every Wednesday and Saturday, it becomes routine and boring. Have you tried jumping in the shower with him? How about walking around in some new, sexy underwear? Have you tried talking to him about what turns you on and be sure to do it before you go to bed? Do you tell each other how important you are to one another? Do you speak words of love in a genuine way, not just do it when you want in his pant?
There are lots of things that you need to consider and they all start with open, honest communication. He can't just say he doesn't have the urge and drop it at that.
BTW, just because he doesn't jerk off, doesn't mean you shouldn't. Why don't you? Sit down next to him with your laptop, turn on some porn and whip out your dick and jerk off in front of him. If he doesn't respond to your sexuality, then you might want to consider burying him because he is likely dead, you guys are only 25, afterall.
Keep us informed.