Crawlback number

The phone number you use to call up your ex to try to get back together with them.

"So, after your ex told you that you're a failure as a man, that you were a failure as a husband, and that you would've been a failure as a father, you're still going to try to get back together with her? How are you even going to reach her? I thought she blocked you from everything."
"I think I still have her cell in my incoming call history, so I'll just use that as a crawlback number."