I agree with nightangel. Communication
and lubrication might be good for you
both.
You're very lucky to have a partner who is
so generous to go through all of that even
if she is not really in the mood. A lot
of women prefer oral to sex, that's
nothing new. More women orgasm to oral
than they do to sex.
If your wife is having an orgasm during
oral, you could try having her wait. That
might keep her more in the mood during
sex. Then you could give her an orgasm
after the sex if she doesn't orgasm during
it.
I will have to agree with angel on the 45
minute thing too. Even five minutes of
giving someone oral is a chore and a half
for me. Maybe you do not realize just how
lucky you are.

Sounds like your
wife should be getting roses every night.
