You must understand the definition of "poont" first. Poont is sort of a kind of emotion, or more like a way to describe certain emotions. It can actually be used to describe a wide range of emotions. Usually, the act of being emo, sad, dwelling on some drama, or even being bitchy or disappointed about something. "Poont-faced" is the act of being. Acting or having the facial expression that makes it obvious you are "poont" or being "poont".
1-Your friend just found out his girlfriend cheated:
"Man, dont get all poont (poont faced) about it, you knew she was a ho anyway."
2-You and said friend drive by the movie theatre to see whats playing and the movie you want to see is sold out. Youre disappointed:
"Dammit! We should have gotten here earlier!"
Friend: " Dont get all poont faced about it, we'll watch something else or catch the next showing."
3-You and your girlfriend are out dining and youre ex girlfriend is there and stops to talk to you. Your new girlfriend gets upset and bitchy.
"Dont be childish. She just said hello. Now stop being poont (poont faced) and let's have a nice dinner."
4-"Dont get poont, it'll be OK."
"You look poont-faced, whats the matter?"