Grownup Time!

Nine year old Frank Iero and Gerard Way are at Gerard's house, having a sleepover, but Mrs. Way insists that they have to be in bed by a certain time. This confuses Gerard because his mother is always telling him that and she still hasn't let him go to bed at the time he wants. According to Mrs. Way, you have to be "grownup" to go to sleep at your own time.
Gerard and Frank both want to be grown up, what can they do to achieve that?