Michael Gambon and the tale of two families: Married Harry Potter star, 76, and his mistress Philippa Hart, 51, enjoy rare outing with their son at Tom Stoppard's 80th

They raise two children together in London while he still lives part-time with his wife in Kent. 

And Sir Michael Gambon and his mistress Philippa Hart, who is 25 years his junior, enjoyed a rare family outing over the weekend as they took their son Tom to playwright Tom Stoppard's 80th birthday party in London.

The actor, 76, looked every inch the doting dad as he clasped tightly onto his nine-year-old's hand on his way to the bash, held at the Chelsea Physic Garden.

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Quality time: Michael Gambon, 76, and his mistress Philippa Hart, 51, enjoyed a rare family outing over the weekend as they took son Tom to playwright Tom Stoppard's 80th birthday party

Quality time: Michael Gambon, 76, and his mistress Philippa Hart, 51, enjoyed a rare family outing over the weekend as they took son Tom to playwright Tom Stoppard's 80th birthday party

The Irish thespian looked happy to be spending quality time with his family as he led his son into the bash by the hand - with his partner Philippa holding onto the other.

Dressing up for the occasion, the actor looked typically smart in a linen blazer, layered on top of a crisp blue shirt and beige chinos. 

Following in his father's footsteps, nine-year-old Tom mirrored his style by sporting a blue checked shirt and navy strides of his own as he headed in to the party, with his parents by his side.  

Family man: The actor looked every inch the doting dad as he clasped onto his nine-year-old's hand on his way to the bash, at the Chelsea Physic Garden, with Philippa holding the other

Family man: The actor looked every inch the doting dad as he clasped onto his nine-year-old's hand on his way to the bash, at the Chelsea Physic Garden, with Philippa holding the other

Like father like son: Following in his father's footsteps, nine-year-old Tom mirrored his style by sporting a blue checked shirt and navy strides of his own as he headed in to the party

Like father like son: Following in his father's footsteps, nine-year-old Tom mirrored his style by sporting a blue checked shirt and navy strides of his own as he headed in to the party

Michael has no doubt formed a close friendship with Stoppard over the years, having starred in a number of his plays at the National Theatre - including Undiscovered Country, Rosencrantz and Guildenstern Are Dead, The Real Inspector Hound and Dalliance, to name a few.

Alongside the Harry Potter star a whole host of other high profile guests were in attendance, such as Damian Lewis, Jude Law and Dame Maggie Smith.  

Meanwhile Michael and Philippa were seen happily chatting to their son on their way inside, clearly glad to be relaxing together in sunny London.

Boys will be boys: The actor shares two children with the set designer - Tom, nine, as well as a second son Will, seven

Boys will be boys: The actor shares two children with the set designer - Tom, nine, as well as a second son Will, seven

Suits you: Dressing up for the occasion, the actor looked typically smart in a linen blazer, layered on top of a crisp blue shirt and beige chinos

Suits you: Dressing up for the occasion, the actor looked typically smart in a linen blazer, layered on top of a crisp blue shirt and beige chinos

The actor shares two children with the redhead - Tom, nine, as well as a second son Will, seven.

The couple have been together since 2000, when they worked together on Channel 4 series Longitude.

However, their relationship is far from traditional - Michael is still married to his wife, Lady Anne Gambon.

Still going strong: The couple have been together since 2000, when they worked together on Channel 4 series Longitude

Still going strong: The couple have been together since 2000, when they worked together on Channel 4 series Longitude

The actor splits his time between their marital home, a £5million country pile in Kent, and Chiswick, West London, where his two sons live with his set designer mistress.

While his wife was initially said to be devastated by the news, leading Gambon to move out of their home, he returned to Kent shortly afterwards - with his wife presumably coming to terms with the arrangement.

Michael and the mathematician have been married for over fifty years, having tied the knot back in 1962 when he was just 22 years old, and welcoming son Fergus together, now 53.

The other woman: Michael is still married to his wife, Lady Anne Gambon (above), who he lives with in Kent. They have been married for over 50 years and share a son, Fergus, 53

The other woman: Michael is still married to his wife, Lady Anne Gambon (above), who he lives with in Kent. They have been married for over 50 years and share a son, Fergus, 53

Despite being a father to two children under ten in his seventies, his former co-star Hetty Baynes admitted he was very much a hands-on dad, despite his age.

Speaking after the release of their TV series The Casual Vacancy in 2015, she revealed: ‘Michael was never happier than when his boys were on the set.

‘They were so sweet and you can see he absolutely adores them. But I’m sure they run him ragged. Having a child in later life can be an exhausting thing, but it brings so much joy.'

She then added: 'But Philippa is amazing. She does an awful lot of the work and she’s absolutely delightful.’

Birthday boy: Michael has formed a close friendship with Tom Stoppard (right, pictured in 2008) over the years, having starred in a number of his plays at the National Theatre

Birthday boy: Michael has formed a close friendship with Tom Stoppard (right, pictured in 2008) over the years, having starred in a number of his plays at the National Theatre

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