I used to deliver room service on the graveyard shift at a 5-star hotel when I was in college. While women were almost always polite and would at least wear the robe that was provided, it seemed at least every shift there was at least one dude in his skivvies or a towel, etc., and usually more than one.
Over about three years I saw everything and so did the housekeepers. The women were always annoyed and I never got what the hoped for pleasure the dudes were after. You gotta admit it's a little perverted. You call for towels at midnight and just happen to be wearing one when you answer the door?
In my case I think the guys just assumed that me being another guy, that I wouldn't care if they were barely cloth or naked, and they were right. I couldn't have cared less. You almost expect a dude in his boxers when you deliver beer and a ham sandwich at 1am in the morning.
I saw dudes getting blowjobs, having sex, jerking off etc. There were plenty of escorts available and there's something about hiring one that will cause a guy to feel comfortable pulling his dick out while you pour the champagne? The heat of the moment I guess and hey they always tipped well...