This story happened in Universes 4, 6, 18 and 20, a while before Buu Saga. (Or maybe a while after it, who knows, nothing makes sense in Dragon Ball movies anyway.)

Gohan and Vegeta are flying towards the source of the gigantic chi they can feel next to Trunkses and Goten's ones, which are rapidly diminishing.

'We have to hurry,' Vegeta says, sweatdropping.

'The kids are going to die,' Gohan pants, not out of tireness; he's panting out of fear.

Suddenly, he stops abruptly in mid air, causing Vegeta to do the same. With his expression now totally casual, he says: 'Wait a minute, Vegeta, I thought you weren't playing in that movie. And where is Videl anyway?'

'Dunno, man,' Vegeta shrugs, equally casually. 'She said something about being too busy loving you and being 100% faithful to you and sent me in her place.'

Meanwhile, at Bulma's bedroom...

Totally naked, Bulma and Videl are having lesbian sex in scissoring position.

'I'M CUMMIIIING!' Bulma screams. 'AND I'M A THOT!'

'I'M AN EVEN GREATER THOOOOT!' Videl screams, cumming as well.

'Oh, my sweet angel,' Gohan says, obviously touched.

Then, fear returning to their expressions, the two Saiyans resume flying.

When they arrive, they see Broly, transformed into Legendary Super Saiyan, laughing hysterically. Goten and Trunks are obviously underwater.

'Heh. We're far stronger than we were 7 years ago,' Vegeta comments. 'He poses no threat to us anymore.'

'Vegeta, can't you sense his power has increased as well and, once more, he greatly surpasses us?' Gohan scolds.

'Dunno, man, Dragon Ball characters' ability to properly gauge the opponents' chi was always pretty vague and plot dependent anyway,' Vegeta sighs. 'Now let me do as the movie's badly written script says, brainlessly attacking Broly while you dive underwater to save the kids.'

'On it!' Gohan says and dives while Vegeta begins receiving a beating from Broly.

And so, Gohan searched for his brother and Trunks underwater, until he found out they were being saved by Eighteen while jacking off to her since they were at it.

Thus, Gohan emerged from the water and attacked Broly, transforming into Super Saiyan 2.

'Wow, Gohan's power is as awesome as 7 years ago against Cell,' Vegeta thinks. 'But I'll pretend not to notice it, since, later, at the Budokai, I'll retcon that statement, saying he has been weakened.'

That moment, Piccolo, who also has received a beating from Broly, regenerates his body, showing his feet for the first time on screen.

'Vegeta!' he snaps. 'Do you know what I just thought of?'

'That Salagir is the greatest foot fetish in existence, along with Disney, Dan Schneider and the guys who made Your lie in April intro?' Vegeta guesses.

'No! That we can defeat Broly if we push him to the sun with our united blasts,' Piccolo explains.

Meanwhile, in Otherworld...

'I'll go help them too,' Goku announces to King Kai and teleports.

'Which makes you wonder why he didn't help them against Androids in Universes 12 and 14,' King Kai comments.

And so, Broly got pushed into the sun and killed, except in Universe 20, where he came back and killed them all. Now go and get lives till the next time I update.