he doesn't seem or mention being shy, he mentions they're blowing him out when he's saying his age. Either don't mention it, or if they ask don't give a straight answer and make it into a joke, or try and hold a solid tone like you say.

If he worked at a wal-mart or a mcdonald's or something and didn't want to mention that to the girl because they've been consistently brushing him off, would it be wrong to say that he's a butane lighter repairman just to get a laugh out of it, and earn a little bit more flirting? He's not being misleading or being shy about it, he's avoiding a problem that other girls have had with him and taking a negative interaction and turning it into a positive one showing that he can be funny.

I don't see any difference between the two.


...and like I said, if this is happening early in interactions before he can build enough attraction, then come back to the age difference once she's more comfortable around him later. He doesn't have to hide his age, but he doesn't have to comply to her request for an answer at that moment either.