My guess is that since Jack was celibate in the original series, I guess some people (incorrectly) interpreted that to mean that he was gay? He doesn't really have a lot of choices either way. The Scotsman? Ew.
He wasn't really celibate, he was shown to be attracted to girls but very shy.
This trait was played a lot in the recent episodes in question, even with a girl he's known for a while.
Also their early relationship was hilarious