I told my gf my pin years ago, no idea if she still remembers it. She has never used it though. I only told her it so she could use my card to get money out and do the shopping while I was at work. She ended up waiting for me to get home because she didn't feel right using my card.
I know her pin too, had to get money out for her a bunch of times when she was pregnant (each time, 3 kids). I haven't had any reason to use her card at any other time though and doubt I'll ever need to again.
We'll have been together 12 years next month.
I wouldn't tell anyone else my pin. I refused to tell my brother it last year when he wanted to borrow my card for a night out (after losing his card, phone and keys the night before).