She has absolutely been to their apartment. Probably more than once. Marc likely regularly invites her over for dinner or lunch or just to sit and compare notes over what they've picked up over the past few weeks.

Steven looks up. "Oh, yep, that's my apartment all right," he says, and reluctantly disengages so he can pat around for his keys. Layla gets a warm, if sleepy, smile once he finds them. "Guess I'm gonna have to bid you goodnight, then."