Your brother suggested you helping his girlfriend out with her workouts so you've just got back from the gym with her... She's very hot and sweaty. You tell her that the only thing left to do is the post-workout stretches... So she starts stretching in front of you, bending over giving you a really good look at her arse, but she doesn't know you're watching! After a few minutes, you tell her that the stretching works better if she's naked and the clothes that she's wearing are restricting her stretching! You naughty perv! That's your brother's girlfriend!