That afternoon Derek goes down the cafeteria and sees that Mark and Meredith are already seated at a table. Mark has his left hand on Meredith's thigh. Derek watches at Mark leans over and whispers something to Meredith. She giggles and kisses him.

Derek walks over and puts his tray down.

Der: hey
Mer: hey, how is your consult going?
Der: good. So Mark, you are chief.
Mark: I am
Der: and you two?

Mark: we live together
Der: you live with the residents
Mer: yes,
Der: and that's okay the Chief of Surgery living with the residents
Mark: yep, because I say its okay
Der; okay then

Meredith's pager goes off

Mer: I gotta go

She stands up and kisses Mark and runs back inside

Der: she never did that with me
Mark: what
Der: kiss me at the hospital
Mark: she's changed a lot Derek
Der: I see that.

They stay and talk and then both their pagers go off.

Later that day Mark is looking at the OR board when he feels a pair of arms wrap around his waist. Mark stiffens, its not Meredith. Meredith comes around the corner and sees a nurse with her arms our Mark.

She walks over and pulls the nurse off of him and pushes her into an oncall room.

Mer: who the hell do you think you are?
Betty: I'm Betty
Mer: so Betty, why were you man handling MY boyfriend
Betty: please just because he slept wit you once doesn't mean he is your boyfriend.
Mer: really

She walks to the door, she pokes her head. Mark is looking at her.

Mer: come here please

Mark walks in

Mark: yes
Mer: I hate to sound petty but Mark who did you have sex with last night

Mark smile

Mark: I don't know if I'd call it sleep but you
Mer: and the night before
Mark: you. And the night before that and the night before that.
Mer: see, Mark and I live together
Betty: I see

Mark goes to Meredith and passionately kisses her. Betty rolls her eyes and starts to walk out. Meredith pulls back

Mer: touch him again and I will rip every limb from your body

Betty walks out and slams the door. Mark goes and locks the door.

Mark: you are so hot when you are jealous