after reading the complete englsih wikipedia entry on FEnris ^^ i would sum up the story like this:
Because of a fortelling(supersticious gods that starts well ^^) Odin and the other Æsir intended to bind Fenrir.
The way of doing it was by creating strong bands/colars/chains and trick Fenrir into wearing them to test if he would be strong enough to break them.
They produced iron bindings and others which he broke free from. In the end they let dwarves craft from 6 mysterious materials a chain.
Fenrir was cautious and didnt trust this smoth material and said to the Æsir, that if they put that on him and he wouldnt be able to break free, they wouldnt release him.
The gods said sure we would release you .... so Fenris asked them that one should put his hand in his mouth and Tyr did so.(dude really where is your sence of reality are you mad?)
The Æsir then put the band on Fenrir and he wasnt able to break free and they didnt release him and so Fenrir bit of Tyrs hand.
Betrayel through sacrifice with outcome that Fenrir was bound afterwards till Ragnarök, then at worldsend in a battle it is fortold he will swallow Odin and Vidanr(REvenge) will afterwards kill Fenrir ... then again till that happend the Moon the Sun and everything already is swallowed aswell so ... GG and dont fuck with Fenrir
edit:
i changed the lore of the first page to:
After a dark fortelling by which Fenrir the brother of the underwolrd goddess Hel, he would consume Odin at Ragnarök.
The Æsir betrayed Fenrir and tricked him into binding. Fenris only satisfaction was by biting of Tyrs hand.
Ever since he is waiting