Nothing, she's your brother's wife!

You pull your hand out your your shorts.

“No, I'm sorry, I should have locked the door. Not that I meant to do this it just…”

You smile and blush.

“Sorry you had to see this.”

She blushes too and smiles, Shyly.

“Didn't see a thing… And if I had, it would have been h..."

She gulps. Did she mean to say 'hot'?

"No worries, sisters can keep secrets, right?”

You stand up and hug her.

“Thanks. You're the best sister in law I could ask for. My brother is the luckiest guy alive.”

She smiles warmly. And returns the hug.

"You should come down, your Dad’s almost ready with grilling enough meat for a small army."

"As usual. I need to go to the bathroom first, just go ahead”

She nods and leaves - you look at her firm ass as she goes.

Your brother IS a damn lucky man. She's a real hottie. A real shame he got her first. Well. Can't help it...