Actually, IIRC, the OP’s wife wants nothing to do with him, Danalan, so I don’t think it’s so much an issue of him having underactive libido.
And AskNott, I hate to break it to you, but lots of women have felt amorous soon after being screwed. Sex isn’t always a better cure for sexual frustration than masturbation.
DougC - here’s what I’m talking about:
Doug - the reason she would complain is because of those pesky things we call “vows” that you take when you’re married. That whole “till death do us part, in sickness in health, won’t cheat on ya, good times and bad, yada, yada” spiel.
People who cheat are not trying to save anything, LET ALONE the relationship. If there’s problems with sex in the relationship, um, well, the couple could, uh, oh let’s see - WORK IT OUT! Get counseling! Cheating on someone is never a solution, nor should it be considered an option!
I’ll get off my soapbox now.
I can attest to having been on Paxil®, and yes, the drive does disappear. Rather disturbing for a 20 year old woman. Also, I yawned a lot, could not get to sleep and my right ear clogged up. Very glad when I got off that stuff. 
I seem to have confused you, CrazyCatLady, and it’s probably my fault for using an obscure phrase for masturbation (coming unscrewed.) I was trying to say that I don’t think masturbation is an effective way to fend off the desire or the ability to have sex.
Because they love the person they’re married to and don’t want to hurt them? Otherwise, what I said before. If people spent more time getting to know all these important facts about their intended, like what their sex drive was, there would be fewer reasons to cheat.
[Nitpick]:
VIAGRA IS NOT AN APHRODESIAC!!
It’s an “anti-impotence” medicine: it just makes the plumbing work better.
[/Nitpick]
I can think of lots of reasons why the men aren’t getting as much sex as before marriage, and mostly the reasons are children. Well, that and the first rush of infatuation (or love, if you prefer) fades, and the tedium of day-to-day life takes the bloom off the old bed-squeaking whump whump whump of the headboard.
I don’t want sex to be tedious. I want to enjoy it every time I get to enjoy it (which, with 4 little kids, isn’t as often as my husband would prefer). But many nights I’m desperately tired. Or my monthly hormonal cycle is on the downswing and it would take an act of God to allow me to get aroused. Or perhaps hubby and I have had an argument and the last thing I feel like doing is climbing in bed and acting loving. I mean, sex (for me, and I think for a great many women) is more complex than hump hump hump ahhhh! There’s all these facets. (And before anybody makes a crack about my sex life, I am quite happy, thank you, though for one week each month I would like more, and its opposite week, I would like none - hello, hormones.)
I’m sure these firemen can find ways to at least ‘ease’ themselves. But unless they’re doing half the housework and cooking (when home, I mean, obviously this isn’t possible when they’re pulling overnights at the station), and if their wives are like me, starting to head for bed and finding a dozen things that must be done before they can get undressed and lay their heads down…well, geez, I don’t know what they expect? Exhaustion, not to mention even a little bit of resentment, is a serious libido-killer. Before marriage, these issues didn’t exist, or existed differently.
I hear romantic comedies do wonders to eliminate the male sex drive. Watching “How to Lose a Guy in 10 Days” almost made me forget about sex.
A little SportsCenter cleared that problem right up, however.