A twinger is someone with red hair that looks just like you or someone you know. They are your red headed clone and are more often than not a complete stranger.
"The other day I was walking down the block and I saw my brother's twinger!"
"His what?!"
"His TWIN-GER. His ginger twin. Someone who looked JUST like him, but with red hair."
When you notice that someone changes the way they do there hair act or dress for a guy, and you did the same change. Usually happens when a guy that two girls like admit what they like in girls. Example: curly hair or short shorts.
Dude: did you see Hannah and Brittany today?
Other dude: yeah they'retotally twinpressing on you!