He should wait until he has been wart free for 6 months before being sexually active to make sure he has cleared the infection. HPV is not transferred by sharing towels.
Hello,
HPV is one of the most common sexually transmitted diseases. It can be due to having sex with multiple partners or with infected persons. They are contagious when in contact with the skin of an infected person. It is also possible to get warts from using towels or other objects used by an infected person.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.