Oh yeah, for sure.
Im the oldest. Sister is a few years younger and brother a few years younger than that.
Brother and I shared a room, we often got spanked in our bedroom so he saw it many times. And spanking were almost always bottomless, so he saw everything many times. I also saw him alot too.
Sister did see me get bare spanked a few times though. It occasionally would happen in the living room, and a few times we got spanked together. So did see her as well, but way less than me and my brother.
Most embarrassing one was probably when I was 12, maybe 13 ? I dont remember exactly. But I got caught smoking.
Dad brought me to the living room, called my sister and brother down. Took off my pants and underwear and beat my butt right there in front of them.
It was warning to them about what happens if you ever smoke.
Damn, that was embarrassing. Bottomless, at a little bit of an older age, getting spanked in front of sister and brother. Got it standing up at first, then bent over hands on the couch. So they saw EVERYTHING