Buttholes

[NudeBaG]

Guys.
Ladies.
Writers.
I know I don’t speak for all of us, but…
Buttholes aren’t always visible just because a character bends over.
Butt cheeks hide buttholes.
The idea that just because a guy bends over you can see ‘everything’ is both unrealistic and disturbing.
Unless it’s prefaced beforehand via description of having ‘no butt’, it just doesn’t work.
This is admittedly a weird rant, but it is equally weird how many stories revolve around a visible ‘butthole’ just because the character bends over.
Justify the exposure

[RaccoonBatteryStaple]

Buttholes aren’t always visible just because a character bends over.
...
This is admittedly a weird rant, but it is equally weird how many stories revolve around a visible ‘butthole’ just because the character bends over.

To your implied point, the size and shape of the buttocks will play a part, but it's largely a question of how far the target bends over and the viewing angle of the observer, isn't it?

I'm pretty sure if you're sitting in a chair a few feet away from me and I bend over to touch my toes for some reason, unless I make a point of clenching my cheeks they're going to part and you're going to get at least a glimpse.

If you're standing and I bend partway over to pet a dog, then yeah, you aren't going to see anything.

[NickTwisp]

Also, how far apart the person spreads his legs. I've seen images of guys bent over where the viewer can clearly see his testicles & part of the penis.