Plan it out

First things first, you need a plan.

When? You decide midnight would be best, give Your parents and brother ample time to fall asleep. it's in 3 hours.

Where? Your backyard, but you need a reason to be out in case you get caught... stargazing should be good enough.

Clothes? you decide to wear what you normally would to bed, panties and an oversized tee.

when? 2 more hours...