He was a graduate of Saracens academy system where he progressed into the first-team squad. Crumpton spent time on loan with Plymouth Albion in the RFU Championship where he made four Championship appearances and featured in the British and Irish Cup.[1] But it was cut short as he signed for Premiership rivals Harlequins on a loan until the end of the 2013-14 season.[2]
On 5 March 2014, Crumpton agreed a move to Bristol who play in the RFU Championship on a two-year contract from the 2014-15 season.[3] but was extended for two further seasons until the end of the 2017-18 season. However, on 5 February 2018, Crumpton left Bristol by mutual consent to resign with Harlequins on a permanent deal until the end of the summer 2020.[4]
On 1 September 2018, Crumpton scored a try, on his competitive debut for Harlequins. Quin's beat Sale at home and Crumpton's second half try topped a brilliant competitive debut for Crumpton in Premiership Rugby, playing for Harlequins.[6]
He was forced to retire through injury in June 2020.[7]
