The Brentford striker and Man City defender clashed in City's 3-1 victory on Monday night, with Walker speaking to referee Jarred Gillett as he reacted furiously to something Maupay said to him in the closing stages of the Premier League clash.
It was unclear exactly what the war of words was about, with both managers Pep Guardiola and Thomas Frank batting away questions about the incident post-match.
But it's didn't take a genius to come up with a theory, with Walker's name in the front and back pages over the last few weeks after separating from his wife and children over his relationship with another woman.
A professional lip-reader has suggested that was precisely what the bust-up was over, telling the Daily Mail: "Walker approached the fourth official and shouted: 'I'm gonna knock him [Maupay] out'. To which Stuart Attwell replied: 'Shush'.
"Walker then said: 'Ref he spoke about my kids, he spoke about my kids, not once, but twice'. Maupay then responded by saying: 'That's a lie, that's not fair, I promise you now'."
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Former Liverpool and Tottenham midfielder Danny Murphy reacted to the scenes on talkSPORT, saying: "If you're going to do things away from the pitch, they're going to get brought up on it - that's life. Take it on the chin, don't be running to the ref."
Former Crystal Palace owner Jordan agrees, saying it's on Walker to resist the taunts from his opponent.
But he added that there's a clear reason why Maupay wanted to get under his skin - because he's not a very good player.
"I think he [Murphy] is right," said the White and Jordan host on talkSPORT. "I think it's unpalatable but it's the reality of the circumstances. Footballers have been doing it for years, cricket does it, it's called sledging and it's part and parcel of the game.
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"It's up to Kyle Walker to rise above it and not be affected by it, because if he is affected by it he's being affected by the opposition, which he shouldn't be.
"I wouldn't do it [what Maupay did], because I think you beat people with talent, you don't beat people by putting them off their game, but it's gamesmanship.
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"Maupay is a bit of a wind-up merchant. He was a bit of a big-time Charlie at Brighton and they had problems with him there, and then he goes to Everton where he's about as useful as a one-legged man in a backside kicking competition, because he couldn't score any goals. Now he's gone back to Brentford and he's creating a little bit of mischief around the place.
"But Kyle Walker is an infinitely better player than Neal Maupay will ever be. He's one of the best full-backs in world football, he's playing for one of the best teams in world football, he's an outstanding player and he's an outstanding England player.
"He's on a different level to Neal Maupay and the only way players like Maupay can get anything on Walker is getting in their head, and so he's giving it to him.
"But this idea that in this society we've all got to look out for each other - cobblers! It's a football match, it's not a village bowling green.
"I think If Kyle allows himself to be affected by that, if he's feeling a bit sensitive about it, then that's on him.
"Maybe Maupay did cross the line, but he doesn't need to get the officials involved. There was an age-old scenario - and I'm not advocating for this - that he deals with him in the tunnel, and then we'd have seen how much Maupay has to say for himself, because he probably would have legged it into the dressing room.
"But Kyle has just got to get over it. Neal Maupay is an irrelevance, and he only becomes relevant if you make him relevant. So Walker should have been able to contend with it, he should have been bigger and better and I know Maupay might have said something that was really offensive but so what? Too many people react to what people are saying to them, when the people who are saying it are irrelevant.
"You have to own your own decisions and you have to take the consequences of them.
"If you go around kicking cats, like Kurt Zouma did, then people are going to call you a cat kicker - so the moral of the story is don't kick cats.
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"If you don't want people to make fun of your private life, then don't go slinging it around and selling stories to a newspaper to manage other problems that might be coming down the pipe.
"We've all got to live with the consequences. I walk around with people saying to me, 'You're a failed football club owner' - we've all got to live with the things we've done in the past, true or unfair."