A couple of years ago we were having the bathroom tiled by a guy my friend had recommended that had done some work for her.
It turned out that the tiler and I had gone to school together (same year) but we didn't know each other at the time because the school was separate boys and girls.
So obviously we got chatting and I dug out some old school photos (leavers ball etc) and sure enough there we both were.
It was a fiddly job (lots of awkward corners and things to try and tile around) which would have meant a second day, but he said he'd stay late and finish it. Obviously we really appreciated this so when I was cooking dinner for myself and my husband I cooked a dinner for the tiler too. I mean, it wouldn't have occurred to me NOT to, if I'm honest. He was grateful. Said he wouldn't have to go cooking for himself when he got home.
We added each other on Facebook and we had a few mutual friends.
About a month later he was doing a small job in my SIL's house. I'd warned him about her in advance. She stood behind him supervising him while he was working, told him under no circumstances would she allow any 'tradesmen' to use her toilet. He ended up having to pop into the local pub (the only one in the small village where she lives) and ask if he could use theirs,
I had to laugh though when he said to me forget about dinner, she literally didn't even make him a cup of tea!
She's a snobby cow at the best of times, so I wasn't even surprised when he told me, but there's just no need to be that rude and disrespectful towards anyone.