Millie gives me a handjob

Millie leans forward and takes my cock in her hand and starts tugging on it. She does so for a while, then says:

"You know this is black mail, right?"

I laugh and say:

"It is working though, is it not?"

Millie sighs and rolls her eyes and picks up the pace she is jerking my cock. I reach out and start fondling one of her breasts, but she pushes my hand away, saying:

"That is not part of our deal."

She puts the hand she is not using to jerk my cock on my balls, starting to fondle them. She keeps going for a while, then says:

"I cannot believe I am sitting in the back of my car with my tits out jerking off my step-son."

"Oh yeah, talk dirty to me baby." I say and laugh.

Millie picks up her pace of jerking. She clearly knows what she is doing I think to myself.

"Millie?" I whisper.

"Yes?" Millie replies.

I say something inaudible and Millie leans forwards to hear me, her tits hanging over my lap, and then I whisper:

"I am going to cum on your tits." As my load shoots out of my cock, splashing onto her big tits.

Millie screams out in anger, looking down at her cum covered tits and jumping backwards. She gives me an angry stare as I lean back saying:

"Come on, it's not like you have not had those covered in cum before."

Millie grabs my shirt and uses it to wipe her tits, then her facial expression softens and she says:

"Is that it for this thread or any comments on what will happen next?"

I look down at the comments section to check.