You stay and watch, with unexpected results

You can't take your eyes of the sight before you, even though you know you should remove yourself from the room before Rachel wakes up - and possibly freaks out, by finding you watching her masturbate. But the scene is just getting better by the moment, drawing your eyes back to her crotch while she's starting to work her way out of those pants...

What happens next is pretty far from what you'd ever expected however, and your eyes widen in shock while Rachel finally manages to free her sex of those trousers and the blanket. Rather than the soft and female mound that you'd come to look forwards to, what comes into view instead is a real and quite impressively sized cock...!

"What...?" You just barely manage to keep from gasping out loud, but can only stare and gawk at the sight in front of you.

Luckily Rachel hasn't noticed your presence at least, but just continues moaning and breathing heavilly while stroking that long hard shaft of her's. Just a few moments later you can see her tense up, with a sheen of perspiration forming on her lovely body, and it's easy to tell that she's approaching an orgasm.

At the last stages she finally abandons her soft breasts, and instead let her other hand join the first between her slender thighs. By now you're both confused and intrigued by the unexpected addition to her body, and watch with even more fascination as she's spreading her legs, pushing her sack out of the way, and start playing with what looks like the entrance of a very female vagina...

You don't have much time to process her strange anatomy however, as she suddenly heaves and shudders in a fit of intensive pleasure, before that massive cock erupts to spray load after load of sticky semen onto her slender waist.

Knowing that she's bound to open her eyes any moment now, you try and tear yourself away from the astonishing sight, before she can catch you red-handed with staring at her body like this...