I don't think it's a destiny thing AT ALL. I don't believe in that sort of thing. I definitely think that BRIAN doesn't think there's anything special going on other than Brian's own fabulousness and this sweet boy that IS NOT boring.
Yet, they DO fall in love and become each others loves of their lives. That wouldn't happen if they didn't have amazing chemistry on a bunch of levels. So, I think it's, yes, Brian was giving him the first time treatment, but yes, it was so good because hey, whether they're Brian and Justin just meeting or Brian and Justin in love, they're still Brian and Justin.
Afterward, the next times Justin stalks Brian, he's clearly growing on him. Even more.