There's a whole subreddit for sink pissers and sink shitters. Something is wrong in the head with those people.

"Honey you're being hysterical". Works every time. Just add some mansplaining and she'll come to her senses. Might want ot refer to "that time of the month" to seal the deal.

Yeah my mother won't talk to me, how do you know?

It's not uncommon for it to be from childhood trauma, like being bullied in the school bathroom or being shamed/bullied by family. Although they will usually insist that it is for other reasons like it being faster.

And I'd say "in your own house" is the key phrase here. As in, a house that you live in alone and don't share with other people that also need to use the sink or basin.

It’s about efficiency. I can get up in the morning and immediately go brush my teeth. As I’m brushing my teeth I lay my hog on the sink and do the deed. I finish much quicker and get ready for work in about 7 minutes using this strategy.