He was a graduate of Saracens academy system where he progressed into the first-team squad.
[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.
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.
He was selected for England U20s squad to take part in the 2012 IRB Junior World Championship in South Africa starting with a match against Italy U20s on 4 June 2012.