Andy Murray once tried to make his international team mate Liam Broady's life a misery by ensuring his first speech at a Davis Cup welcome dinner was a disaster.
Now the world number two is planning to make Broady's life just as uncomfortable in the unforgiving world of grand slam tennis.
For the first time in 56 matches over 11 years, Britain's twice grand slam champion Murray finds himself drawn at Wimbledon against a fellow countryman and he admits that playing his 22-year-old colleague will feel "weird".
For a former champion long buoyed by support from the home fans, Murray could instead find the showcourt crowds cheering for a lad from Stockport - home town of Murray's only rival for the accolade of Britain's best player ever, Fred Perry - when they play on Tuesday.
Broady reckons he is playing the part of Leicester City, the 5,000-1 no-hopers who went on to win the Premier League. Barring one thing; he believes he's probably an even bigger outsider to pull off one of Wimbledon's great sensations.
It has all left the tournament's second favourite Murray admitting he does not quite know what to expect with their first round match.
"It will be interesting. Obviously never happened before, not for me anyway," Murray told a news conference on Saturday. "Liam's a good guy. Works hard. I would imagine we'd probably play on one of the big courts, so a big experience for him, as well. Yeah, look forward to it but, I mean, it will be a bit strange."
Broady inhabits a different world to Murray, scrabbling around in Challenger and Futures tournaments to make his way in the game as the world number 234.
Yet on the Davis Cup beat, they have got to know each other pretty well. When he first joined the British team, Broady recalled, Murray was vociferous in trying to ensure he went through the newcomers' initiation ceremony of having to make a speech at his first welcome dinner.
"He had obviously never been to one of the dinners before, so wasn't sure exactly what he should say," Murray smiled. "We were telling him the wrong things to say and hoping he would stand up and actually say them." Disappointingly for him, though, Broady "did fine".
However fine he is on Tuesday, though, he will only be a launch pad for Murray to kick off a campaign in which, even Roger Federer concedes, the Scot and Novak Djokovic are the outstanding favourites.
Djokovic won their last battle in the French Open final, leaving Murray able once again only to marvel at the world number one's extraordinary level of excellence.
"His consistency and drive over the last few years has been incredible. I don't know if that's ever happened before, where someone's pretty much gone over a year consistently reaching the finals of tournaments," said Murray.
"In an individual sport, if you have a really bad day, wake up, you feel terrible, you lose at this level. He hasn't had really any of those results or those matches over the last few years. That's very impressive."
To break the Serb's dominance, Murray has just been reunited with Ivan Lendl, the former Czech great who coached him to Wimbledon glory in 2013.
Their first week saw Murray lift a record fifth Queen's title, leaving the number two seed to enthuse: "It actually gives a bit of extra confidence, because I know last time we worked together, it was very successful. I trust in what he says."