Downtown Love refers to people who are never in relationships for long because they are always looking for something new, and/or always craving more attention.
When you send a message to someone via your choice of social media, and the person you are trying to contact leaves you on seen, but they still make posts and interact with other friends.
Zeph: Hey, Rebecca! How've you been?
Rebecca: *reads message but does not respond, also makes a post about how no one messages her*
Zeph: Wow, downspotted by Rebecca again...
Nice downs is used when people say/do something as dumb and unthoughtful. It could also be used to describe an abysmal and stupid person. The phrase is short for Down syndrome because people with this illness are known to be mentally challenged.