A storm has been unleashed and who knows when it will blow over.
Right now Mourinho is on a warm weather training trip with United in Dubai but there's no doubt he's already crafting his response to get under Conte's skin once again.
The Italian says he remains committed to his job with the defending Premier League champions but criticised the increased uncertainty managers regularly face in English football. Conte seems perfectly happy; Chelsea seem happy enough as well.
The next day Conte reminded Mourinho that he was once an animated young manager - the former Real Madrid boss famously ran along the touchline at Old Trafford in 2004 to celebrate his Porto team's victor against United in the Champions League.
Antonio Conte says it is up to Chelsea whether he stays at the club or not.
'Committed' Conte will not walk out on Chelsea
The former Juventus and Italy boss, whose side are third in the table, said that goes with the territory of working at Chelsea and does not happen at other clubs.
Their enmity stretches back to early last season, with Mourinho accusing his Chelsea counterpart of humiliating him with the scale of his celebrations as United fell to a 4-0 defeat at Stamford Bridge in October 2016. A gust became a storm.
On the negative side, while Antonio Conte's squad have remained relatively unscathed by injury there is a creeping sense of unease among Chelsea supporters that the lack of respite is starting to affect the Blues boss and his players. This is football, our job is very hard as you know, everything can change a few times. So wrong question and obviously a strong answer and I don't blame. Speaking about the same, the Portuguese has added that for him, this is the 'end of the story'.
"I think when a person insults another you can expect a response", Mourinho said.
"He shouldn't back down because when he walks in [the Chelsea] dressing room, the players are going to go insane; he's going to get an applause from everyone".
"The date for him to be back to training with the team was around end of January, beginning of February, so let's hope his feelings are better and we have him with us as soon as possible".