I'll pencil you in 

To make definite plans to meet with someone. As in writing your name in an appointment book.

I'm free Thursday afternoon, so I'll pencil you in.

I'll pencil you in by jafo May 19, 2004

I'll pencil you in 

To sexually assult/stimulate someone with a pencil, usually rubber end first for safety.

Oi, come here you silly slag... I'll pencil you in!

I'll pencil you in by Horny B April 27, 2008

I'll pencil you in 

It literally means that someone will give you the details of something, but is usually just someone trying to give you the runaround.

"What happened with you and your girlfriend?"
"I'll pencil you in later."

I'll pencil you in by Jessica May 20, 2004

i'll lightly pencil you in 

To pencil someone into a schedule but using a light amount of pressure. This way, as you know they will always cancel, when you erase, there is no visual indent of their name in your schedule.

Guy: sorry I keep cancelling on you, would you like to go to the cinema on Friday?

Girl: yes, I'll lightly pencil you in.
Guy cancels
Girl to friend: I am glad I only lightly penciled him in, as there is no indent to remind me that he cancelled AGAIN!

i'll lightly pencil you in by Lightly pencilling January 4, 2014