Yup, we were today years old when we realised that Lindsay's brother, as well as her mum and other siblings all starred in the movie.
So who did they play?
Well, remember that boy who ended up at Camp Walden by mistake, because he didn't realise it was an all girls' camp?! Yep, thanks to IMDb we know that this was Lindsay's brother, Michael Lohan Jr.
Meanwhile, Lindsay's mum, Dina Lohan, and siblings - Aliana and Dakota (who also goes by the name of Cody) Lohan - were all extras in the airport scene where Hallie arrives in London and meets Martin the butler (you know, the one where they do their secret handshake).
We can't believe we never knew this until now...
Fans are equally shook by the revelation, with one tweeting: "FYI that little boy in The Parent Trap whose the only boy in the camp is Lindsay Lohan's brother #themoreyouknow."
While another added: "I did not know Lindsay Lohan's brother was in The Parent Trap with her, wooooow I feel so late!"
And one wrote: "Weird that Lindsay Lohan and her brother and sister all were in The Parent Trap."
"WOAH I totes just spotted Dina Lohan in The Parent Trap!", said a fellow fan of the movie.
In case you need a reminder, The Parent Trap was based on a remake of the Hayley Mills fronted 1961 film of the same name.
The story follows identical twins Annie and Hallie (both played by Lohan), who are separated at birth and each raised by one of their biological parents, unaware of the other's existence.
Things go awry when the pair meet for the first time at a summer camp and realise they're sisters, and they go on to swap places so they can experience each other's lives, while also attempting to bring their parents back together.
Chosen for YouChosen for You
Most Read StoriesMost Read