Taking the vaccine now won't hurt but there are also no studies indicating that it helps over 26. Thats another reason why doctors don't recommend it. And to answer your question again, yes you can infect your wife even if you wear a condom with your GF.
Correction on the typo: I meant four (instead of for) most common types
You can take the vaccine at any age I think. The age limit of 26 is mainly based on the fact that after 26 it assumed that you have already been infected with the types covered by the vaccine. Also, as far as I last read the vaccine has only been tested for 26 and younger, but there is no reason why it won't work for older people. You can ask your doctor about the vaccine. Note that since you are older than the age requirement, insurance won't cover the cost of vaccine, which is around $500 for the three shots. Keep in mind that the vaccine only covers the for most common types of HPV. HPV has many other strains that could effect the genitals/mouth.
I havent been with another woman in over 20 years. Im am still married but seeing a great girl who I have not slept with yet.
The problem is that I am 42 years old and still married. Too old for the vaccine. And not wanting to give this to my wife if we have sex again in the future.
Also consider getting vaccinated against HPV (which protects against the four most common HPV strains). The vaccines requires 6 months to be completed. It is taken in 3 shots.
Safe sex is 50% protection. Look at it this way, if you have been sexually active (>3 partners), you already have it! And if you date someone else who is sexually active, she has it too. Sorry but unless you are planning on being monogamous with one partner for the rest of your life, getting this std is inevitable. Don't let this stop you from enjoying sex.