Penile Cancers are very rare - only 1500 cases per year in the USA.
It is likely that your body will just clear the infection.
I can appreciate your concerns. I'm 54, first diagnosed as High Risk HPV positive in 10/11. My husband and I have been in a mutually monogamous relationship for 25 years so this has been a surprise/shock, especially considering I tested negative in May 2011 and also 3 years ago. Did they test your wife for HPV 16 and HPV 18 strains? I had to go back and ask my GYN specifically (after reading on my own) for testing on these strains. These are the main strains, from what I understand, that lead to anal cancer. HPV 33 and HPV 73 do, too, but I don't know if they can test specifically for these. I would be sure to tell your doctor(s) and dentist your wife has HPV and you've been exposed. I asked my husband to do this, also suggested he go in to his doctor to make sure that the lightly and occasionally bleeding hemorrhoids he's been having are really just that.