What it means
Paperclipping is when someone, often an ex, pops back into your life out of nowhere with a casual text, just to keep themselves on your radar, then vanishes again. They have no real intention of meeting up or committing, they just don't want to be forgotten. It's named after Clippy, the old Microsoft paperclip that kept resurfacing whether you wanted it or not.
Usage examples
"My ex is paperclipping again, a hey stranger text every few months and then radio silence."
"Don't reply to the paperclipping, he only resurfaces when he's bored, not because he cares."
"She wasn't trying to get back together, she was just paperclipping me with a random you up? at 11 p.m."
"He's classic paperclipping material, drops a nostalgic text, sniffs for attention, then evaporates."
Where it comes from
The term comes from Clippy, the old Microsoft Office paperclip assistant that used to pop up uninvited with fake-helpful energy. Dating slang grabbed that image and turned it into paperclipping for when someone keeps reappearing in your messages just to remind you they still exist, then disappears again.