When we were college-aged, my brother and I hosted a few parties at our house. Because there was copious amounts of alcohol involved, trouble ensued sometimes. Our first party, one gal had bought her own alcohol to supplement the keg provided, and proceeded to get blotto, then toss her cookies onto a guy's expensive jacket - and our sofa that was it was sitting under. When she called the next day to retrieve her purse, she had no clue what she did until I told her. She was very embarrassed and apologetic, but that was it. We made a vow to never invite her over again, even though we were on good terms with her.
Not that I ever host anything now, but that is one of the reasons why nobody would be allowed to drink too much at my place if I did.