Jennifer Aniston at LAX Airport

Jennifer Aniston arrived at LAX with a bodyguard by her side to catch a flight out of town on Monday, just a couple of days after throwing a huge party for her fiancé Justin Theroux's 42nd birthday. The star-studded bash was held at Jennifer's home in Bel Air and brought out celebrity friends like Jimmy Kimmel, Ellen DeGeneres, Kristen Bell, and Ben Stiller. The event also marked the one-year anniversary of Jen and Justin's engagement.

Now that the party is over, Jen is getting back to work. She's likely leaving LA in order to continue promoting her recent comedy We're the Millers, which was released in the US last week. Jen recently hit the red carpet alongside costars Jason Sudeikis and Emma Roberts in NYC, and the stars followed up the big premiere with a more casual press day at the Crosby Street Hotel.