...m...my grandma?” you asked awkwardly.
“You want me to turn myself into your grandma. Ohhh, that's interesting, hun.” Your shapeshifting girlfriend states as she clambers on top of your dick. "And y'know, I've never been this kind of this kind of stuff before, now after you saying this, I've always wanted to try some GILF and young stud."
As you begin thrusting her moans become lower and huskier, her hips widen pressing her now bigger and shaggy rear into your groin. Her whole body into a fat belly, her nipples enlarge and breasts swell out and sag to a big G-cups. As your girlfriends face begins to pop and change shape, her brown hair becomes thicker and brightens into a sexy grey as it shrinks to her face. Your girlfriends formerly dainty round face has formed into your old grandmother’s mature, old face. Finally slight muscles fill out her arms, back, and legs as barely noticeable wrinkles work their way into her skin.
Now your transformed girlfriend is completely your own grandmother, she shouts,”Keep it up, Dear. Granny need it, Need it so bad!” Upon which you release your semen.
“Well, that was a great sex, dear. Ya lasted much longer than your grandpa. What do ya say we make this another round just between me and my dearest grandson?” Your shapeshifting girlfriend(or should you say grandma) says as she cuddles up next to you.
Picking up her role playing queue, “Oh I would love to do it again, grandma.” Grabbing her by the ass and pulling her in for a kiss.
“So, what else do we do now?” She says, holding your face in her hands.