DEAR ABBY: I recently attended a friend’s party that was being given to celebrate their son’s 18th birthday. I thought it would be cheeky and fun to buy him a risque card from an adult boutique, thinking everyone would get a good laugh, and we’d have something to roast the young man with. When he opened the card, he had this look of horror on his face, ran out of the room all teary-eyed and went d…