Are you a picker or do you just leave it? Does it depend on what you're wearing? Or where you are? Perhaps its comforting to you to have something shoved between your cheeks lining your butt crack. Or perhaps you dont even notice.
Me personally - I am a picker. I do not like my butt highlighted with thread nor do I find it comfy. If I have a wedgee - I probably havent noticed it OR during athletic events, I figure - why bother picking it if its just going to crawl right back up. I mine as well deal with it and then when I'm done - I change clothes.
I know some people like to put their butts on display with their butt crease so vivid for all to see. they purposely hike their shorts up to seal them to their body so it leaves no imagining necessary for the human eye. It's attractive to some and others need to just staple their butt cheeks shut.