Oh yes, multiple times

You were enjoying the view you had of your girlfriend on top of you naked her tits bouncing with each thrust into your pussy. Her hands knew just where to touch you to get you going, and before long she had you orgasming multiple times back to back.

In the middle of one of your orgasms you feel her reach down and take the cock firmly in hand. You weren't sure what she was doing, but than you feel a sudden cold feeling deep in your pussy and than the cock slides into you easier. Huh must have been lube, what a cool toy you think. Looking down at your pussy you see your lips engulfing the thick cock and the weird milky lube leaking out of you.

A familiar scent reaches your nose, but it's hard to think of what it is with how clouded your mind is. Before you can recognize the danger of your situation another orgasm hits you wiping the thoughts from your mind. Doe releases more lube from the fake cock, you aren't sure why though as it seems plenty wet enough to you.

She keeps that up for another hour before you pass out from exhaustion. Seeing that you are out cold she empties the rest of the cum into your poor little pussy. Leaving the cock buried in your pussy to make sure the cum doesn't leak out Doe passes out with you.

You sleep quite soundly until an alarm goes off waking you. Turning the alarm off you see that you are once again alone in bed. Moving slightly you feel a hardness between your legs, throwing back the covers you expect to see your own body back and are disappointed to see a pair of tits on your chest and that a strap-on was inside your pussy. Removing it you see a torrent of the lube flowing out of your pussy.

The pungent smell of cum hits your nose...oh no that wasn't lube, she was inseminating you all night! How could your own girlfriend do that to you?! Checking the time you see that it's 9:59. You have one minute before you should be changing back. Hopefully she was too late, or the sperm had died.