What's one of the most embarrassing/strange things your parents or a family member cought you doing?

On a wooden post near a railway crossing, someone had drawn quite an anatomically detailed drawing of a vagina. I used to look at it every time I went past and, if nobody was around, I might take my time.

Until the time I felt something grab at the back of my leg and saw it was one of the family dogs jumping up to greet me. Then looked up to see my mum frowning.