This thread is cool though I am not into it like some, but I will share an experience I recall if unexpected cmnm that some may appreciate. non sexual if you want to stop reading.
In HS (senior year, 18yo), me and three friends stayed at another friend's house because we were getting up 6 AM to go camping. The friend who lived there actually got home last (baseball game) after we hit the sack early. I was sleeping in his room in a sleeping bag. I hadn't packed much clothes, plus we were never modest, so I slept nude. That's really how I slept anyway, including on the camping trip.
At 6AM his dad knocks on the door. My friend is still out cold and guess the alarm failed to go off. He poked his head in, and I said good morning. He asked whether I should be up already, to which I said yes but figured alarm hadn't got set correctly (pre cell phones ). So he told me to get up and he'd get me a towel for the shower.
I immediately realized I had just said we should get up but also that my clothes were in my pack and I was nude. I couldn't think of a way out that didn't sound stupid or rude so I got up while he watched me climb out of the sleeping bag.
He asked me a couple of questions about the trip while he walked me down the hall, flipped on the bathroom light and reached for a towel in the adjacent linen closet.
He came into the bathroom and hung the towel up and then we started chatting about a number of things. He was completely normal - think his son (my friend) was nude a lot at home so he wasn't phased at all. Zero improper glances or any sense of improriety under than in my head where I was just standing there naked talking to him. I had no interest or sexual tension other than it would look really bad if i got anyorning wood Luckily he had woken me up where I needed to pee but not yet to where my body was waking me up with a boner. But I could tell it was swollen and needed to pee so, being so young, just having a thought about it was enough to make it fluff just a bit. Again, he didn't look, boring story, I just remember being on the edge of massive embarrassment and has given me some appreciation for cmnm situations.