Dating
✅submarining
✅ghosting
✅orbiting
Submarining is what someone

does when they date someone for a bit, disappear without explanation, and then reappear, also without explanation.
If the person you've been seeing ghosts on you and then three months later casually texts you asking if you want to go see a movie, that's submarining. It's basically as if they've been underwater and out of sight for weeks or months only to reemerge in your life, leaving you confused and frustrated.