Really, Maul wasn't even sure that Ariadne could do the emotion of mad, so seeing her in a state of even mild irritation really was all that he thought she was capable of muster. He almost started laughing when Ariadne demanded to know when he and Reaper had gotten hitched.

"We eloped!" Maul said, trying hard to keep from laughing and not succeeding very well. "Neither of us just flat-out announced it. Reaper and I can be a bit private like that." He'd just allowed the information to trickle out naturally by word-of-mouth.