...Dad here seems disproportionately worried about the gay bit will look to his daughter, as opposed to the fact that he's dating a kid more or less her age. Or rather, the author seems to be playing up that aspect of it, when any character talks about it explicitly... I know it's somewhat a genre thing, as well, but this is well-written enough that it feels a tiny bit of a cheap move to me.
Like, even if they had the best of intentions, hearing from your parent a year after they've divorced that they're going out with someone their age could be... pretty deeply upsetting, frankly, for not totally unreasonable reasons.
Ah well. The subtext is there just fine, I'm just nitpicking.