Genitile Warts

I would like to enquire about genitile warts!!
My husband went to the doctors yesterday and has been diagnosed with them and referred to the gum clinik. It caused a huge row because the doctor said that it could only be transmitted through sex. The only other partners I have had were 20 years ago and there were only 2, I am 99.9% certain that it isnt my husband either mainly because of the way he has gone about everything. So the question is how can this have happened??
As you can appreciate we are not actually speaking at the moment!! I feel completly devastated and upset feeling that I have been accused of something I haven't done and our marrige is on rocky ground.
I have agreed to attend the gum clinic to be tested but I am also upset that I have to do so to clear my name with someone who should trust me and who I have been married to for 17 years.

Is there any other way of catching them?? The only thing that I can think of is that he has athleets foot and often has a quick scratch of the goolies probably without washing his hands.

Help!!!!