They Breadcrumb
As you could probably deduce, "breadcrumbing" is the act providing tiny, non-committal morsels of interest to effectively string someone along. You know, like the occasional fire react on your Instagram story selfie or a "Heyyy" text here and there. If the object of your desire is doing this without actually pursuing you, they're keeping you on the backburner in case someone else doesn't work out. It's a harsh truth but it's a sign to cut them off.