Your (or your partner's) cock is hard and ready...
You (or your partner) bend over and spread those sexy ass cheeks wide open...
You (or your partner) spread lube all over that throbbing cock to slide into that tight little hole...
AND THEN...
Damn, your hands have lube all over them!

Option 1, wipe the excess lube on her butt? She may not like it, and you lose the ability to grip her butt for leverage. Too slippery.
Option 2, wipe the excess lube on yourself somewhere? That always feels ... gross to me. I don't want lube on my leg or anywhere. Ha
Option 3, wipe the excess lube on a towel? ...So you keep a lube towel next to you every time you have anal sex?
Option 4, wipe the excess lube on the sheets? Um, no. And that assumes you always have anal sex in bed.
I dunno. We're taking option 1 these days, but I'm kind of not a fan of having lube all over her butt. I want it in her ass, not everywhere.
What do you do?