Tunneldumb and Tunneldumber

Lesbian #1: The G train always takes so long between stops, especially since it's not going in a tunnel.
Lesbian #2: But it does go through a tunnel.
Lesbian #1: Yeah, but I mean a tunnel under water.
Lesbian #2: Oh, yeah, okay, it's not going under water.
Lesbian #1: I always wondered how they make those tunnels.
Lesbian #2: They have one of those machines, that goes in circles.
Lesbian #1: Oh, okay...
Lesbian #2: You know, the one that goes in circles really quickly?
Lesbian #1: Yeah... [Pause] But when they build the tunnel in the water, does it go in the water, or under the water?
Lesbian #2: Under the water.
Lesbian #1: Oh, right.

--G train