We had to climb another 'flight/set of stairs' to get to the roof.
He tripped on the bottom 'stair' and almost fell.
He waited at the foot/bottom of the 'stairs'.
(..) Heh-heh. Yup. Tip your waitresses. I'm here all week. To save you from further awkwardness... ...know that I'm comfortable with the two of us climbing the stairs in silence. Oh, yeah, okay, me too. Zip it, lock it. Put it in your pocket. - So you and Leonard- - Oh, dear God. (..)2008 TvShow: The Big Bang Theory Title: The Cooper-Hofstadter Polarization Season: 1 Episode 9