It could be in your hobby/providing life or in your RW life.
What's the worst idea you ever got "between the sheets?" that you wish you didn't try?
I mean, we all probably have done one or two things we regret the morning after or a few minutes after we've done the deed.
Sex in the cab of a small Toyota pickup truck with 2 bucket seats. Mine and the girl I was with, our backs hated us for weeks after that. We could had done it on the hard metal surface of the short bed but we didn't have any thick blankets and it was also cold outside.
Food! Specifically with honey and whipped cream. It looks fun in Porn but it's not, it's messy and gross and the clean up afterward involves throwing all the sheets and pillow cases into the wash.