Aww, that's cute! Reminds me of when me and two friends came back from a lecture and just collapsed on a sofa like a bunch of dominoes. It was late in the day in winter, the day of the week was our busiest one and we were all cold and very tired. Best of all, we had a practical to attend in an hour! We just fell asleep instantly, still wearing our coats and shoes, and woke up when it was time to go. Which was quite impressive, as I don't recall anyone setting the alarm!