It could mean one of the two is playing the other just for the attention, rather than both parties being shy or awkward. Open relationships often contain specific rules and boundaries, just like monogamous relationships, but "no sex with anyone else, ever! Take stealthing, for example, which is just a form of sexual assault. Submarining, a newly named trendbegins when someone with whom you have romantic involvement, ghosts — or disappears from your life without notice — only to resurface, with no apology and acts as if no time had passed. Can be applied to people who feel outside the gender binary, or it can be applied to persons who feel that their gender isn't fixed, but variable — changing from day to day.
Like a knot of toads, they create a late-night chorus of their favourite opening refrains:
Ghosting, Caspering and six new dating terms you've never heard of
From Tinder it spread to Bumble and a few thousand copycat apps. One is classy, old world, and stuffy; the other is crass, lewd and very present. In the natural world, spiders have webs, and millennials have thirst traps. If you're getting submarined, pro tip: It's a setup that only works in deeply unequal situations — if you're getting firedoored, you're constantly feeling frustrated and only occasionally satisfied.