The pair have had their differences on the field in the past and Smith dubbed Flintoff a "big baby" throughout last winter's tour of South Africa, as extracts from Michael Vaughan's new book revealed on the eve of the six-day Test with Australia in Sydney.
Brought together with the common goal of beating the Australians, however, Flintoff said of the sledge: "That is quite tame to be honest. Myself and Smithy had some tussles during the series in England two years ago. We competed hard when we were on the pitch and it was no different in South Africa.
"It is very much what happens on the pitch stays there, and afterwards we can have a laugh about it over a beer. "
The England captain, Michael Vaughan, says adjusting quickly to conditions in Pakistan holds the key to his side's chances. The tourists have two three-day games to prepare for the first of three Tests, starting on 12 November in Multan.
"We've got players who haven't played in the subcontinent and it does take a while to get used to the surreal conditions out there," Vaughan said.
"It's a different type of cricket and we're going to have to be at our best to get used to the conditions quickly."
England arrive on 26 October in a country coming to terms with the recent earthquake which has claimed more than 38,000 lives. Vaughan is hoping his side can do their bit to help the relief effort by maintaining the positive style of play which has brought them six successive Test series victories, including the Ashes triumph.
"Going to Pakistan now for me is just a chance to hopefully put a few smiles on some of their faces," he said. "We've played some great cricket and we know how passionate they are about their cricket."
Vaughan has told the England and Wales Cricket Board he is happy to remain as captain for as long as the board wants him.
Vaughan said: "I'm sure there will come a stage where the players would like to hear a different voice and like to have a different direction. I'll stay for as long as they want me."
The England captain is well aware of the task facing his team, and has urged them to put memories of this summer's Ashes glory to one side.
He said: "Pakistan are a very talented team. Bob Woolmer has got them playing well so it's going to be a tough challenge."