I (M19) got made fun of by my friend (F20) for washing my asshole?

I (M19) got made fun of by my friend (F20) for washing my ass?

Yeah so basically the title lol. My friend and I were talking on the phone as we usually do, and my friend said something like “imagine washing the inside of your ass that’s gross, especially with a rag.” And I was like “um yeah I do that” and they were like “what really? That’s gross” and then they asked their entire family if they washed their asses and they all said no, just the outside lmao apparently I’m a gross weirdo now. I’m super mad at my friend and I probably won’t talk to them for awhile but if I did, exactly what do I say to them? Also apparently I’m gross now but I refuse to believe washing your asshole is gross lmao.

TLDR: My friend thinks it’s gross to wash your asshole. I said I wash my asshole, they asked their whole family and they said they don’t wash their asshole. I’m mad at friend now.

Edit: so to clarify, inside the asshole meaning inbetween the cheeks, not penetrating the anus lol. To clarify further on how I know this isn’t a miscommunication as I see how someone could think this is a possibility, it’s not, as they asked their dad if he washes his ass and he said “I was the top of my ass”