A cat or young child throwing up. One bight when DS had gastro we went through all our bed linen.
It's been roughly fifteen years - but I remember getting up three times one night when VorSon (then about five or six) was sleeping on blankets in my room because he wasn't feeling well.
No kidding, after three "simultaneous eruptions from both ends", I left the washing machine going with load two, the dryer going with load one, and load three in the laundry basket and took him to the ER. Where we had to wait because he was no longer throwing up. We got home Saturday morning as the alarm for work was going off at 6 am. (I hadn't turned it off due to being a bit busy...) and the only diagnosis was along the lines of "he must have eaten something that disagreed with him or he's got the 24 hour bug that's going around - seems to be over the worst of it now..."
I still had laundry to do when we woke up...about noon. I have no memory of what Ambrosia Hino was doing that night - she might have been working the night shift at the burger place and gotten home only shortly before we did...