Your girlfriend is now a total milf. Still bearing resemblance to her old self, she's older and mucg curvier, hefty pale breasts pushed up by what was probably a push up bra, a soft middle leading to very wide hips.
"What do you think, hun?" she said in a husky voice.
"Um, you're older," you state the obvious.
"Yes," she smiles. She then slowly turns around, letting you admire her body. "But do you like it? Do I look better?"
You want to say yes, but you also don't want to imply you like her better now than her usual self, even if you probably do find her milf-self arousing you. "I think you're beautiful."
"Nice," she purrs. "I'm so horny right now. I don't know if it's this body, or just this scenario, but I want to fuck, to have some fun with my boytoy."
"Right now?" You weren't used to her acting so forward, usually she was much more reserved.
"Right now," she smiled. The curvy milf grabbed your ass and gave it a squeeze.