Poseur or as many people say "poser" is someone who tries to fit into a group of people in an exaggerated way. like a skater poser will wear DC shoes and ride an element deck with spitfire wheels and independent trucks(companies which quite a few non skaters will recognize) and carry it by the truck to school and just stand around holding it not doing anything and will brag about things he probably hasn't ever landed and when asked to do them, he will probably say he doesnt feel like it.
he will probably rub his shoes against the griptape at home to make it look like hes a hardcore skater and cut the nose with scissors for kickflip marks.
Me: try to treflip that ledge man
Poseur: shit DUDE its so small. I need a big GNARLY ledge to do my tricks.
Me: okay it has a big side.
Poseur: Duhhhh... i rolled my ankle yesterday(hell say this really fast)
Relating someone to the type of person that goes to a party and just watches.
1. John! Its just a quiz! Instead of studying just come chill with me. Fine you party watcher
2. I can't believe Sue goes to work 45 minutes early everyday, shes such a party watcher!
3. Omg! You're so lame you party watcher!