Not a morning person

Overheard on the bus:
Perky blonde commuter with bright pink lippy: “Do you mind if I open the window?”
Greying, balding commuter in grey suit: “No.”
“No, you don’t mind, or you do mind?”
“I do mind. I am cold all day at work.”
“Oh. Well, have a good day.” Muttered under breath: “Grump.”
“Yes. Sometimes I am.”