When she comes home from work the next day, a little later than usual, she makes a beeline for you.
"Hey," she says, raising your head. "I was a little bit of a bitch to you yesterday, wasn't I?" Of course, you don't respond. She raises your head, manipulating your mouth. "It's okay, Jen, I knew what I was getting into," she makes you say. "Anyway," she says, "I have something to show you."
She pulls down her pants and underwear, revealing a massive cock. She giggles. "Like it?" she says. "It comes off." She grabs, and with a wet *pop*, her penis and testicles come off into her hands, leaving the parts you'd grown familiar with unmolested beneath. "Thankfully - I don't know how one in five run around all day with these things - but now that my girlfriend's a love doll, I thought it'd make sense to get one."
She spends the next ten minutes or so wrestling the penis back onto her crotch. "Dammit, the girl showed me how to do this..." Eventually, you hear a sucking sound, and a satisfied sigh from Jen. "Okay!" she shouts. "Let's do this then."
And so she fucks you. Or, not even - she masturbates into you. You are, after all, a masturbation aid. She touches your face, your breasts, your ass, she kisses you, and you can feel all of it, but you can sense in her the familiar half-satisfaction of masturbation. Ultimately, she lies next to you, sighing.
"Well..." she says... "it's better than nothing."