I've never been very good at "coloring inside the lines," especially when the lines are merely hinted at.
The one-on-one stuff is barely implied, mostly pasted on by random interpretation. Neither Tracy nor I was big on VD (that's what she called it

), but our partner Annie was, so we'd take her out on an evening of dinner & drinks & flowers & such. One or both would take her to bed, depending on how tired we were by then & who had to wake up first.
Excepting the irrationally superstitious, there's no good reason to do VD on the calendar date, much less to make such gestures ONLY annually on that "official" date.
Not everyone follows strict dyadism. That crap can backfire. Like, Nancy started with Dan a bit before me, so considered him "more primary" (yeah, I know...

). I asked her if I could take her out to dinner, or maybe get a bunch of us together. She demurred: "Dan already said he had something planned." Well, Dan is a bumbling meathead

& his "plan" consisted of ordering take-out & watching TV. So, by the time Nancy decided she wasn't amused, the rest of us were out carousing, & she had no idea where.
Nothing prevents anyone from going out as a group, or throwing a party. There are public events that aren't strictly dyadic, & some even encourage singles to attend.