Hello Mr Gaiman I was wondering if it was an intentional choice to show Gabriel and Beelzebub in love without a kiss scene because they are more detached from earth and humanity unlike Aziraphale and Crowley who know about human pleasures and rituals and adapted them.
I don't think kissing scenes have much to do with love. Anathema and Newt kissed when they barely knew each other in Season 1, and none of the other couples who loved each other did. I can't see any reason for Gabriel and Beelzebub to kiss: singing Everyday together seemed much more powerful. Crowley's kiss is about a lot of things but it's not to show they're in love: if you haven't got it by then you'll never get it.
I do apologies, but what the last sentence was about? "…if you haven't got it by then you'll never get it." It doesn't seem like it was about Crowley and Aziraphale. It more seems like it was a slightly condescending way to point out that the asker's ability to comprehend the authorial intent is, to put it lightly, limited. I get it, it could be irritating when the audience is a bit slow to understand everything (but people usually get it, especially when an explanation is provided). But given that the initial question wasn't about Crowley and Aziraphale per se or the meaning of their kiss, and was considerably innocent… Perhaps this sort of response wasn't exactly called for?
I'm sorry if I completely misinterpreted the meaning of the sentence. It just made me stop in my tracks and blink… twice in confusion.
The last sentence means that if a person who has watched Good Omens Season 1 and Season 2 hasn’t got that Aziraphale and Crowley are in love by that point then they will never see it, and that the kiss is not there to signify that they are in love.
The “you” in that final sentence doesn’t refer to the person asking the original question but to humanity in general.
I hope this helps.