Mark was used to Len's looks, so they rarely affected him anymore unless he knew it was something dire. Or about his sister.
"We're sure," he was getting a headache, "So you're taking up with the Riddler now? Get rid of that barbaric clown, finally?" It was a simple question. One thrown out to avoid mentioning where they were heading. Mark hadn't known Harley that long, so he had no idea the implications that mentioning The Joker could have. He simply sipped on his beer and waited for this whole debacle to end so they could head to New York.