[ karkat actually looks slightly flustered at the mention of sponge baths mostly since THAT IS SO.... EMBARRASSING...... AND ALSO GROSS. mostly embarrassing. he recovers extremely quickly though, to his credit. ]

Pretty sure that's a job reserved for newbies. Make sure you scrub them extra hard, Rin, to get the germs out. It shouldn't be a problem from your very nicely toned arms.

[ karkat people don't normally point out when very nicely toned arms that casually??? he has no filter. ]