The actors decided to get together before shooting the first movie in 2011 and soon became friends after gorging on burgers.
According to contactmusic.com, Liam told Bliss magazine: "When we shot the first 'Hunger Games', Josh took me to his place in Kentucky. There was a White Castle (burger restaurant) right by his house and we bought three or four briefcases of burgers, took them back to his house and ate them.
"About half an hour later, we went out into his garden and we threw up together!"
They play Jennifer Lawrence's love interests in the franchise.
--IANS (Posted on 22-11-2013)