It's fine.

[He's just not going to bring up the 'teleported halfway through a wall' idea. Probably not a good idea to put that in Mark's head.]

[He takes the teleporter back and puts it back in his pocket, then starts heading towards the back of the building.]

Any reason you don't want to be let down on the street? I'll still take you to the back - I'm just curious.

[Seriously, why this alley?]