Oh, there's been so many dumb things, how does one decide which is the dumbest?
Maybe the one who insisted putting his foot up on the rim of this big planter on the porch while chatting all the time and then after six or eight times, the planter collapsed under his weight and sent him tumbling down the stairs.
Pretty tame, but really funny considering both his wife and I kept telling him he was gonna break it if he kept doing that.
Or maybe the two that recently took the supplied firewood out of their room's fireplace and put it in the reception room fireplace and tried starting a fire without checking to see if the flue was open or not. I guess the big, bold print on our in room guest information guide about "For the safety of all of our guests, only your hosts can start a fire in the reception room fireplace" didn't quite register with them.
Worst part about it is that any guests staying in that room with the fireplace get the entire fire safety policy read to them during the check in tour and must verbally state they understand and agree to abide by the policy.
Not that funny, but after filling much of the house with smoke, freaking out the other guests who had suffered a home fire last year, and breaking one of only a few rules around here that will get you bounced immediately from the premises, plenty dumb at 10:30 pm.