Unmanned Aerial Boyfriend. A male who constantly follows his girlfriend from a distance to keep track of and deal with any other males she might encounter. Similar in mannerisms to "helicopter parents", except more difficult to spot and not as prone to action. their girlfriend might not know they are there
"Dude, I got paired with this hot chick for the group project!"
"Awesome! did you make a pass?"
"Didn't get a chance. She had a UAB two tables over. I couldn't even spot him until he came over and kissed her!