Kristen Stewart and Robert Pattinson had their heads down this afternoon as they got ready to leave from the Budapest airport! He's been in the country working hard on Bel Ami with his many female costars, and it looks like Kristen was finally able to start that vacation she's been excited for and join him there. The duo is finally back together after going their separate ways while she did press for The Runaways, and he started filming his latest project in England. Her visit to Europe came just in time so that she and Robert could celebrate her 20th birthday — we took a look at her first 20 years with a special slideshow, but maybe she and Robert marked the occasion with their latest round of PDA.