He cut it in New Moon when he first became a shape shifter... He let grow it out because he thought bella liked it better long (were now in Eclipse) and after the fight when he ran away from 首页 (now were in Breaking dawn) he cut it short again... Hope it helps
Well a 年 以前 I wasnt sure if it was in New Moon 或者 Eclipse....and we were out at a park and didnt have the 图书 with us so I asked Fanpop...(and its "who doesnt know that:)
