Ms Murray tweeted a photograph of the Queens Club winner with Chelsea football club manager Jose Mourinho, captioning it “The Special One with My Special One”.
But her proud message did not appear to go down well with her eldest son, Jamie, one of Britain’s best doubles players, who simply replied: “Thank you mum”.
The brothers then swapped a series of amusing messages arguing over who was really the number one son.
Andy Murray joined the conversation, insisting: “We all know you are number 1 son noobs ... Best presents at Christmas, bigger bedroom, blame everything on me etc.”
But his brother was quick to concede, joking that Andy’s success in tennis had turned the tables.
“Times have changed ... Now your bedroom is bigger than my apartment and I’m no longer the favourite son,” he said.
In the end it was down to their mother to end the Twitter squabble.
In a follow-up message to Jamie she clarified: “My Extra Special One xx”