That's awful. Not quite the same, but I once received a text about 19 from my Mum which was meant for my Dad. Something along the lines of 'Spoilt little madam is now stealing from you. I've had enough. Will you deal with her or shall I?'
Spoilt my arse...I'd borrowed my Dad's jumper absent mindedly while leaving for work at 6.45am.
I just replied 'I don't think that was meant for me,was it?'
The silence was wonderful 🤣It took her about 45mins to write a reply,much less harshly worded but firmly reiterating I'd done a Bad Thing. I left it.
Got home after work,walked right past her and apologised to my Dad for taking it without asking. He was bewildered by the fuss and said 'Um...it's fine,I wasn't using it and it's cold in the morning'.
Her face was a picture.She apologised,but was ass kissing for days afterwards.
So yes,I agree with PPs. Let them know and enjoy as they squirm. If they don't say it to your face,they don't want you to know what they're really like/think and will be mortified.
Then keep a very wide berth from the pricks.