The first thing I noticed, that I was originally going to comment on, was that sign in the first panel. "Upspeak", I assume, refers to HRT, a vocal peculiarity associated largely with women, particularly young women. Also Australians, but that seems less relevant. Is that a subtle way of saying "no women allowed"? That can't be the intended meaning, surely?
That led me down a bit of a rabbit hole on Wikipedia so I read about gay lisp and sexy baby voice among other things, which was interesting, but doesn't really relate to this comic. Anyway, all that almost distracted me from actually reading the strip, so I almost missed the weirdest thing about it.
The joke follows a pretty standard form of complaining about gym memberships (you don't go and they're hard to cancel) but hold up a second - that's Barry he's talking to. I'm not sure how old Barry is supposed to be, but Curtis is apparently 11 and Barry's younger, so let's say... 9?
Why is Gunther complaining about gym memberships to a nine-year-old? No wonder he's not saying anything back. What would he say? Is Gunther expecting sympathy or understanding from a literal child? What a weird situation.