Deny it:

“I’m not a pervert!”

“God it makes sense now! You were hard when I came into the room. You’re just another perverted man. Just like your father!”

“I’m nothing like him!”

She laughed, a cruel laugh, “Yeah I guess you're right, at least your father had a real dick.”

You look out the window, trying not to think about what your own mother has just said.

“Come on,” she said, opening the car door.

“What? We’re still going in?”

“Yes.” She walks around to your side of the car and opens your door, “consider this the start of your punishment. You’re going to go shopping with me. As my daughter. Do you understand?”