Did Magnus Carlsen ever have a girlfriend ???

How's this: I don't know if Magnus Carlsen ever had a girlfriend, but Magnus Carlsen and I had played in Norway when I was thirteen years old. I checkmated him in 78 moves. That, I remember.

Carlsen currently has a girlfriend.
In the past, he's had very few romantic attachments due to his extreme focus on chess. His family have tried to enable him to live a normal life in addition to focusing on chess, but in this 2015 interview, Carlsen stated that he's never really been in love:
"Another thing he said last time we met was that once he had the world championships out of the way he would have more time for relationships. Has that proved to be the case? ‘No. It hasn’t. I have time to go out and have fun when I’m at home. But I haven’t come very far in terms of settling down and starting a family.’ Has he ever been in love? ‘I don’t think so. I’ve been infatuated, of course, but not in love. No.’"
On March 20th, Carlsen's manager confirmed that he now has a girlfriend - Synne Christin Larsen (22). You can find Norwegian articles on this here and here. On his private Facebook page, his status is also set to "in a relationship".

I think this Synne Kristin Larsen is a good girl for him.
Not that it does matter so much if he has a girlfriend or not.
She looks nice and serious.

I told Google to translate to English the page that came up from your first link, and the title says "Magnus Carlsen has a boyfriend" loooooooool xD

Oh wow, I just saw he's actually a member here. lol
Of course he's a member, and he's played in online chess battles organised and broadcasted by chesscom. Perhaps all of the modern GMs that you know of have an account here.

Synne Christin Larsen. Is she the "lovely young maiden from Norway" in the limericks thread?
https://www.chess.com/forum/view/fun-with-chess/chess-limericks-1 - #7

he might not be too happy when his rubber duck has to make some space for her in the bath.
"Basically my wife was immature. I'd be at home in the bath and she'd come in and sink my boats." Woody Allen
Read more at: https://www.brainyquote.com/quotes/authors/w/woody_allen.html