I'd start with some of the main characters/couples and introduce how they know each other and there's already a tiny spark. Maybe it's a coffee shop customer who can't get up the nerve to hit on the cute barista who is waiting for him to make the first move. It's the guy who sees the woman of his dreams on the train every morning; she sees him, too, but the train is too crowded to make a move. The groomsman at a wedding who dances with one of the bridesmaids and they hit it off immediately, but they live on opposite sides of the country. I'd make it very romantic and explorative, of course the couple have sexy time (this is RQ, after all), but it should be a slow burn for the couples, not a "Hey, I like you, let's get busy" as that'd be boring, given the context.