Warning: Video contains coarse language

Diego Costa is a closed book. It's impossible to understand what's going on in the head of football's chief provocateur.

In the aftermath of Chelsea's victory at West Bromwich Albion, which secured the Blues' fifth Premier League title, Costa stirred up trouble everywhere from the pitch to the dressing room to Antonio Conte's press conference. But it was just another day for the childish villain, whose psychotic tendencies are as inexplicable as they are entertaining.

Exhibit A: Costa appears to grab John Terry's crown jewels

Uhh, what exactly is Diego Costa doing to John Terry here? pic.twitter.com/ppuVv6Xeqj — SI Extra Mustard (@SI_ExtraMustard) May 12, 2017

Exhibit B: Costa pops invisible champagne bottle

Exhibit C: Costa delivers unexpected thrust

Exhibit D: Costa tells reporter to 'fuck off,' appears to pour Lucozade into eyes

GREATEST VIDEO OF ALL TIME COSTA IS A FUCKING LEGEND pic.twitter.com/wkmo2dmCim — MA | 3 | (@TheLeftWingBack) May 12, 2017

Exhibit E: Costa, David Luiz kidnap Conte from press conference

Exhibit F: Costa gets hands on fire extinguisher