For Chelsea fans, it must be difficult to like their former goalkeeper. The no-show. The refusal to return for preseason. Well, that's one thing. But even after getting his way. Forcing the club's hand. Demanding he be sold to Real Madrid. To then take a shot at his old teammates - and the club itself. There's just no defending the Belgian.
Clearly, he was buzzing after the win against Leganes. While Keylor Navas, who had done nothing wrong in the opening two games, was left brooding on the bench, Courtois was eager to let us all know how easy he had found it in front of Real's back four.
"The communication with the defence is going well, even during the games," he began. “In training, you see that the level is high. I am now experiencing on a daily basis that Sergio Ramos is the best centre-back in the world."
Bang! Take that Blues. Specifically, those defenders who'd played in front of Courtois for four years. Who won titles with the Belgian. Cup finals. You're just not at his level. Well, not now. Not when he is a Real Madrid player. But, after a short breath, it turned worse...
Contrasting the Stamford Bridge experience to the Santiago Bernabeu, Courtois just couldn't help himself.
“It's twice as big, of course, it's a very different feeling," declared Real's new No25. "If you look forward, you only see a wall of people while at Stamford Bridge you can still see the sky or the hotel behind the grandstand."
Just charmin'. Real are the proper football club. With the proper stadium. Chelsea? They're just playing at it. Mix and match.
Courtois' father Thierry has long accused the English media of having it in for his son. But after these latest comments, how can he blame anyone for criticising Thibaut's attitude?
"I think my son was wrongly judged in England from the beginning," declared Thierry on the day Courtois signed with Real. "Now take David De Gea: he was treated completely differently. Do not ask me why, but he was always portrayed positively in the media."
Indeed, it's no secret Courtois had a problem with the Manchester United goalkeeper. Just last season, he had a pop at the Spaniard's style.
"I won't search to do the eye-catching saves if I don't need to," he said. "I try to bring calm to the game for the other players. I play from the back, I handle crosses as well, which is an underrated skill I think."
De Gea's response? Well that's the thing, there wasn't one. And with that, Thierry has his answer as to why his son courts such controversy.
Now don't get us wrong. We want our stars to speak out. To tell us their honest thoughts. But Courtois needs to know he's fast losing friends with his attitude.
Indeed, it's not just those connected with Chelsea whom Courtois have insulted. Just yesterday, his former Atletico Madrid teammate Antoine Griezmann made clear his feelings over the keeper's swipe at the style Didier Deschamps' France employed to win the World Cup.
"What Courtois said embarrassed me because he played for Cholo (Diego Simeone), he knows how it goes, he won La Liga like that," snapped Griezmann.
"They're two different playing styles. There was a time for [Pep] Guardiola and his attacking 4-3-3. Now, there's a time for this kind of 4-4-2."
Speaking your mind is one thing, but Courtois - and his camp - must realise he's going to need all the friends he can get this season. As Griezmann hinted, Atletico and their fans will be gunning for him. There are the pundits just waiting for the first goal he concedes between his legs, as he did against Barcelona and Leo Messi last season. And then there's Keylor and his camp. The No1 furious his decision not to join Costa Rica this week was rewarded with being overlooked for Courtois on Saturday. If Thierry reckons the English press were bad, just wait for the scrutiny his son endures as goalkeeper of Real Madrid.
Unlike with Julen Lopetegui, there'll be no easy passes from the Madrid media this season.