A pityhole is the black-hole like creation of a person who is trying to suck you into not leaving them. They try to induce so much pity in you through heart-wrenching stories that you feel too much pity to leave them.
Guy 1: Dude, did you hear what happened to Christine?
Guy2: The girl whose been crushing on you? No, what happened.
Guy 1: Her Grandma died.
Guy 2: Thats' horrible. You should comfort her.
Guy 1: Also, her boyfriend just dumped her.
Guy 2: Ok... that is bad.
Guy 1: She also said that her house just burned down.
Guy 2: Dude, be careful. She may be pulling you into a
Guy1: Nonsense. Oh, she just texted me that she has cancer.
Guy 2: Ok, she is definitely creating a pity hole. And it's obviously starting to work on you.