You guys, our siblings are racking up wedding no-no's this summer. My BIL and his wife got married out of the country a couple months ago and had a reception this past weekend.
The reception was a couple hours away from where H & I live. We planned to go down Saturday afternoon since we couldn't check in to the hotel early and we brought our dog, so we couldn't really go anywhere in the meantime. The reception was scheduled to start at 6, but we did plan to get there a little early anyway. Around 4:30, we got a call from MIL, completely flustered. Apparently SIL had asked a friend to help her set up the decorations and pick up the cake, but her friend completely didn't show up. She lives in town and had seen SIL that morning for pedicures sooo IDK what happened. H & I rushed to get ready & headed over to the reception. As soon as we got in, SIL was asking us to do a billion different things, then getting upset if it wasn't exactly like she was thinking in her head. (Like, no one would have noticed if one table only had three candlesticks instead of two...) MIL was arranging the flowers (that she picked up the day before) and left when H & I showed up so she could get dressed. SIL was in her party dress, ordering everyone around. We got everything set up before the other guests arrived, and the venue somehow found a cake, and the night ended up going smoothly. At the end of the evening, SIL did NOT help clean anything up. H & I, BIL and one of BIL's friends carried everything out to the cars & boxed up the decorations. SIL carried out her extra clothes from earlier in the day.
This is why it's not great to depend on friends to do things for you. Had SIL hired a vendor to set up & asked the bakery to deliver the cake, she would have had some recourse. Instead, she risks damaging a friendship, and left her new husband's family feeling kind of salty about the whole thing.