Hell yes

"Get the hell out of here," she said. "Geez, can I be more clear?"

"Uh, no, that's plenty." Matt backed up as quickly as he could. Admittedly he could have turned around but he wasn't going to deny himself at least a couple more seconds staring at his sexy sister. Okay, he wasn't going to actually do anything about it but there couldn't be anything wrong with appreciating female beauty, could there?

When he got to the door he gave one last look. Karen had her eyes closed and was going at it full-speed. Really, if he could only snap a photo.

But no, Karen was probably going to forgive him for walking in on her while she masturbated. She would never forgive him for taking a picture of her doing it... after she'd demanded that he leave.

Besides, he suspected he had this image indelibly burned into his brain. He really didn't need digital reproduction to keep it fresh.

"Sorry," he said again as he slowly closed the door taking one last peek.

Back in his own room, he stripped off his jeans and pulled out his erect cock. It only took three strokes before he exploded all over his stomach.

Now all he had to do was wait for Karen to settle down because he really needed to get her advice about how to handle the Amy situation.