Ousmane Dembele was seen laughing at Barcelona's demise as PSG thrashed them 4-1 to knock them out of the Champions League.
The Frenchman left Barca to join the Ligue 1 champions in the summer and couldn't help but beam and giggle as they fell apart.
Ronald Araujo's sending-off proved the catalyst for a mighty PSG comeback, as Kylian Mbappe scored twice to help reverse the tie and win 6-4 on aggregate.
Dembele scored in both legs and netted PSG's equaliser on Tuesday night before half-time, with Vitinha scoring a stunning strike before Mbappe's additions.
Barcelona fans had booed Dembele and brought merchandise mocking him but he had the last laugh.
Ousmane Dembele laughed as PSG knocked Barcelona, his old side, out of the Champions League
The Frenchman scored on the night as PSG won 4-1 to reverse a deficit on aggregate
One fan claimed that Dembele 'really hates Barcelona' on X, formerly Twitter, after seeing his reaction.
'Rightfully so,' one replied.
'He really love Paris,' another suggested.
This was a capitulation of immense proportions for Barcelona, seven years after they beat PSG 6-1 to perform their own extraordinary comeback.
Xavi lost his head on the sidelines, getting a red card for kicking some of the Champions League 'furniture' on the sidelines.
Another member of his coaching posse was also dismissed as tempers flared.
Barcelona had gone unbeaten for 13 games coming into this one and had emerged as a dark horse for the competition, which represented Xavi's last semi-realistic chance of silverware at the club.
Some fans thought it showed his hatred for Barcelona, others his adoration for Paris and PSG
He is leaving in the summer, as announced in January, and they are eight points behind Real Madrid with seven games left in LaLiga.
That's not insurmountable, but Barcelona will need to beat Real Madrid this Sunday if they are to give themselves a fighting chance.