LMAO! How on earth would you possibly know if there is a teeny tiny little puppy IN a room if they don't bark? You just bring wee pads for the pup to use. If he has an accident, I'm sure they wouldn't just leave a terd for evidence.
If I wanted to go and didn't have a sitter, I'd surely sneak him in! No sense leaving him at home unattended, no fun worrying and he would be safe with you. I bring Curly everywhere and she'll stay in my bag and I'll treat her every so often for being quiet and all. She knows if she's quiet in a restaurant, she's getting some of what we have so she'll just lay in her bag next to me and I'll sneak her the goods. No one is the wiser!