WTF Moment - Grown Up Sleepover

A strange situation occurred the MLK weekend.  I am still laughing to myself as I think about it.  My wife enlisted the assistance of a young lady who works in a salon.  The purpose was to get my 3 little girls' hair taken care of.  I came home in between jobs on Sunday and they were hard at work.  Sunday night when I got home, I went into the bedroom to get my clothes for work the next morning.  When I turned on the light, I was confused by what greeted my eyes.  There, laying at the foot of the bed, was the young lady who had helped my wife with the girls' hair.  Keep in mind, this young lady is in her 20s.  My wife was in the bed as well as my two youngest.  Now get the image of sardines in a can out of your mind.  All four of them had plenty of wiggle room. With that being said, WTF?  Who allows another grown person to sleep in their bed. I dont know the answer.