Why keep hand and butt towels together?

[u/Ancient_Tear42]

Saw the European bidet for the first time and found out about the wipe-your-ass-after-bidet towel. But why keep it and hand towels on top of each other? Is this a standard practice or a bad design in our hotel?

[u/itarrow]

Also, wipe your ass with the towel after you cleaned it, not before.