I moved out a week after I turned 18 never moved back in but I know if something had ever happened where I had needed to my parents would have allowed me to. It's hard to say no to your children when they need help. As long as they are trying to better themselves how can you say no? On the other hand I have a friend that is 38 living at his parents out of his choice and he has no intentions on moving out anytime soon he's lived out on his own maybe 2 years total now that is pathetic and I've told his parents several times they need to kick him to the curb.