Yes.

After fucking for about AN HOUR AND A HALF, your girlfriend and sister had finally worn themselves out. Eventually Madame Laura came around and rapped on the door, "Are you ok in there my dear? She hasn't hurt you has she?"

Your sister responded in a very groggy tone, "Everything is good Mistress....the damn thing just kept hitting the right spots...and wouldn't stay down...and it felt good....", she trailed off as she legitimately started drooling just remembering the intense fucking.

Madame Laura just chuckled and reminded them that Katie's card would be charged again if they didn't wrap it up. This got Katie kicked into gear getting dressed back up, and she was about to run out the door when she noticed your sister bent over grabbing her panties. What is that stuck between her...!

"Don't move!" Katie yelps at your sister and dives for you. She manages to grab you without your sister seeing you, and your sister rounds on her.

"W-what's wrong???", she asks as she starts feeling around her cum covered ass.

"Nothing!", your girlfriend replies, "I thought I saw something, but I guess it was just glossy cum...heh..heh...."

Your girlfriend then quickly finishes dressing and races out the door to settle up with the Madame.

After Katie gets back in the car she brings you up to eye level and apologizes, "Sorry Sweetheart, I just kind of got lost in the lust..."

You give her a flat stare, "Oh it's fine, I loved getting slapped by your giant balls as you nailed my sister." The look on her face would have been priceless any other time, but the context of the situation kind of ruined it.

The two of you rode back to her place in silence. When you got there however...