Yep! I crashed a wedding once. They had the reception in a basement nightclub at the hotel I was staying at. Lots of people, was actually really nice. The wedding party got half off their bar drinks, if you knew the "password." Well, drunk wedding patrons being...well drunk! The password was pretty easy to figure out.
So, after enjoying myself a bit, and realizing how late it was getting, I dashed out to the gift shop, grabbed a neutral "CONGRATULATIONS!" card, and wrote, "Thanks for letting M. crash your wedding! You're a beautiful couple, and I hope the best for you. Long lives, all the love, and eternal happiness for you both." I shoved $100.00 in it and left it on the gift table, and went back to my room to pass out.
Somehow they figured out who I was, and what room I was in. After waking up with an epic hangover the next morning, room service shows up with a pot of coffee, a bottle of Asprin, and a plate of waffles. As well as a note, "You have to be the best wedding crasher ever. Enjoy!"
Yep, they bought M. breakfast.
Ten years later, they're still married, and we talk all the time. Became really good friends actually. Fortunately for M., they're the kind of couple who thinks things like this are hilarious, and were even taking bets on how many people would crash their nightclub reception. >.<