What is he doing?! (Picture: BT Sport)

It’s easy to get carried away in the heat of the moment, but it’s hard to explain exactly why Diego Perotti decided to act the way he did after Roma went 2-0 up against Chelsea.

As Stephan El Shaarawy capitalised on an Antonio Rudiger mistake to grab his second goal of the game, Perotti rushed over to celebrate with the Egyptian and the rest of his Roma team-mates.

What followed next was truly and utterly bizarre.

For no apparent reason, the Argentine began to rub El Shaarrawy’s bottom and appeared to stick his finger up the winger’s bum hole.

We don’t know why, we’re not sure we want to know why, but it happened, okay?

El Shaarawy did seem to take it in good spirits and smiled at his team-mate so presumably there’s some sort of inside joke going on (insert gag about the joke being *inside* Shaarawy’s bum cheeks).

For Chelsea, it was a tough first half at the Stadio Olimpico, with El Shaarawy banging in a rocked from the edge of the area inside the first minute to hand the Serie A side the lead, before doubling Roma’s advantage nine minutes before half-time.