You can add a minor's name to you credit card account -- like a child away at boarding school or when travelling. Under US Federal court rulings: credit cards and debit cards are not proof of age (period).

http://www2.ca3.uscourts.gov/opinarch/072539p.pdf

Maybe, the banking administrative laws and rules in the UK do not allow minors to be added to their parents' credit cards? So, Junior just pinched Daddy's wallet and uses his credit card to view porn websites. Hopefully, he doesn't make a purchase with Daddy's credit card and you end up with a chargeback

Adult webmasters are so out of touch with the public's reaction to their being caught watching porn. People get fired from jobs and have negative job references from these events. If your wife catches you watching porn beating off -- the shit may hit the fans. The kids finding out ... the wife leaving with them ... It's not a normal family behavior to watch porn together. We may be exposed to porn all of the time as it is our livelihood but we are the exception. I try not to forget this when dealing with customers or the general public.