My ex's parents were horrendous misers. His cousin was getting married and sent out a stamp addressed envelope with the invitation for the RSVP. We were going to the cousin's to see her new baby and were just going to hand over our RSVP there (and envelope of course). Popped to his parents beforehand and told them this, so his mum went to go their RSVP, but before handing it over she steamed the stamp off the stamp addressed envelope to re-use
knowing fine well the cousin would see what she'd done!
Like a PP mentioned they also took a penknife to the supermarket to cut the stalks off broccoli so it would be cheaper.
The worst was when I went skiing with them to Andorra big mistake. We booked a hotel that was half board so got breakfast and evening meal (usual shit buffet, everything was cold and stale). At breakfast they would wrap up some bread rolls and cold meats in a napkin and smuggle out the butter sachets so they didn't have to pay for lunch on the slopes. They'd then moan on when I paid €2 for a plate of chips for lunch, they couldn't believe I'd waste my money! They were horrified when me and boyfriend went out for a meal elsewhere one night (I insisted as I was sick of the hotel gruel).
On the last day I'd sprained my ankle on the slopes so was obviously very slow moving when going home. BF's grandparents were picking us up and at the time at Manchester airport the first 10 minutes in the carp park for pick ups was free. After that you had to pay the grand total of £1.
The grandparents picking us up were equally tight (and millionaires funnily enough) and refused to buy a mobile phone so said they'd be in the pick up zone at an exact time and we HAD to be there. The flight wasn't delayed but getting through security was slow and they were all literally running to make it to the pick up point. I of course couldn't run, couldn't even get a fast walk and they were getting very pissed off. When we got to the (old clapped out) car, I've never seen people move so fast to get stuff in the boot and in a car. I explained if we had to pay I'd happily pay the £1 but they wouldn't slow down. We made it with seconds to spare and they waffled on the whole journey home about how that was a close one.
I dumped my boyfriend not long after that as I began to see traits of them in him - and he'd didn't defend me when they were trying to make me run with my sprained ankle - and I couldn't be with a cheapskate.
Luckily my DH is the opposite. He'd happily pay £20 extra on airport car parking to be that tiny bit closer to the airport, he's not irresponsible with money but he'd never ever skimp on anything we can afford