Incorrigible was one word for it. Chasing round girls who may or may not want it and getting into pissing contests over his own niece. Will could think of some other words.
But he wasn't going to say anything in front of Calliope, and he couldn't say anything in front of Clio. Apollo had hurt her, but he was also her... brother, past lover, connected-in-a-way-Will-couldn't-begin-to-understand-leader. So, as usual, he held his tongue.
Calliope's question caught him off guard. It wasn't untrue, her assumption – often as not, he was the man holding one of the others back when they wanted to go haring off without a plan – but it surprised him how quickly she'd got him pegged.
Agreeing with her seemed like too much of a sledge against the other Merry Men, something he was perfectly happy to do in their company but not in front of an outsider, so he went for easy self-deprecation instead. "Level-headed as any man who lives in a forest robbing the nobility." He considered Calliope speculatively. "Are you... perhaps... one of the more level-headed Muses?"