Neil Patrick Harris is ''very close friends'' with Sir Elton John and his partner David Furnish.

The 40-year-old actor - who is married to David Burtka - admits David was the first person to know about his plans to have children through surrogacy with his husband and believes the quartet have developed a bond through their love of kids.

He said: ''I ran into David Furnish on a trip and we just confided into one another. 'I have a surprise to tell you: we're having kids through surrogacy in a couple of months'.

''I kind of blanched and then he looked around to make sure really no one was paying attention and he said 'we're having a kid through surrogacy on like Christmas Eve'. So we've sort of bonded through kids.''

The four were spotted together at the 20th Annual Race to Erase MS Gala, held in California, in May, where paparazzi snapped David cheekily pinching Neil's butt, but the actor-turned-producer claims it's perfectly fine to touch each others' buttocks if you're gay.

He explained: ''It suddenly became a story, like 'oh no, he's touching his bum'. When you're gay, you kind of get the bum touching free card.

If that was two straight couples and the guys were ''honking'' the girls' butts that would be like terribly offensive but it's a kin with the gay guys.

''It's like in baseball when they slap each other's butts. It's a normal thing.