Friend's Younger Brother Saw Us Naked

Straight from my diary there are only 2 embarrassing moments that happened to me so here is 1 out of 2.

When I was 14 I had a sleepover at a girlfriend together with another girlfriend here in the Netherlands. It was just silly girl talk but the girl we were sleeping at had really big breasts for her age. So the other girl suggested if we could just "see each other's breasts", for the heck of it. I wasn't shy, neither was the other other but the girl we were sleeping at was a bit shy.

Finally we all agreed to take our pyjama tops off and have a look. Just a few seconds after being topless her younger brother (10 or 11) barged in and said "what are you doing?" so we all freaked out and got dressed again. Afterwards we could laugh about it but it was somewhat embarrassing.