John Travolta and Robin Williams crashed wedding

John Travolta and Robin Williams once crashed a wedding together.

The American actors decided after a night of drinking together in Santa Barbara, California, they would join in with the celebrations next door to the bar they were at.

John said: "We were having fun, starting to relax, when we saw there was a wedding next door. We figured we'd crash it."

At first, guests didn't realise the actors - who were both TV stars in the late 70s, when the nuptials took place – were the real stars of shows 'Welcome Back, Kotter' and 'Mork and Mindy'.

John, 55, added: "They figured out who we were. Some guy yelled out, 'Hey, they really are Mork and Vinnie Barbarino!' "

The pair were reunited on the set of their latest film, comedy 'Old Dogs', but their off-the-wall antics and on-set jokes proved too much for some of their co-stars to cope with.

John's wife Kelly Preston, who plays Robin's love interest in the movie, said: "The hardest part of being in a scene with any of these guys was not laughing and ruining every single take.

"And if you did laugh, the director just let us go with it, because they're going to be goofy and try to make you laugh."

'Old Dogs' – which is released next March - follows a pair of ageing sports stars played by John and Robin who are charged with looking after a pair of seven-year-old twins Robin's character never realised he fathered.