Shows you her tits

Pulling her red bra completely down, the woman's massive tits pop out as your cock is pointed directly at them.

"Is that what you've been wanting this whole time?" she coos as she stares at you stroking yourself over her. "Do you want to see Mommy's tits while you jerk yourself off in front of me?"

Just then, you hear a knock at the door. "Brother?" you hear from the outside. "Is everything OK in there?"

Fuck. It's your sister, Kelly.

Before you can react, the woman quickly locks the door, kneeling down in front of it. She whispers to you, "Come on, baby boy. Give me your cum all over your mommy's tits while your sister waits outside for you."