@Josh103  
Yeah that’s a possibility too.

@Amethyst_Crystal  
I think the way he acts when he first encounters Discord makes it clear he does respect Discord. At least, his power.
 
I like to think Tirek really did give the medallion as at least a sign of respect to Discord (his almost sarcastic voice when doing so contradicts that, but ah well), perhaps to give the medallion a new meaning, but when Discord showed that he withheld information, Tirek, being the short-tempered centaur he is, went back on that.

@Amethyst_Crystal  
TL;DR  
Tirek respects Discord’s power and is smart enough not to fuck with him.  
Until he can, that is.

@Josh103  
We can at least assume Tirek is not as powerful as one alicorn before he attacks them, and not as powerful as Discord before he attacks him.  
The alternative is he was really considering keeping Discord as an ally / buddy, when he first presented that amulet, after thinking he’s won.  
Maybe because he didn’t think he could get enough magic anytime soon to overpower Discord.

@Amethyst_Crystal  
I’m still trying to figure out how powerful was Tirek at what points.

Discord was absolutely far more powerful than Tirek when they first met.
 
It could be argued that Tirek still couldn’t even touch Discord until after he gained power from the Mane Six, he had no reason to keep the alliance after banishing the 3 princesses.
 
Discord helped Tirek become stronger much faster than he could’ve done alone, what with the chaos god’s teleportation skills and helping to capture ponies.
 
Discord has only himself to blame.

@DanielTepesKraus  
Point taken.

@Mayojar77  
Yeah. So a guy and a girl in a relationship on a tv show means that’s the extent of their personality?

@DanielTepesKraus  
Except for the fact that they’re both guys in a relationship.

@Mayojar77  
No, that’s one of the few jokes that is about them being gay. There’s episodes where you’d never even know they were a gay couple.

@DanielTepesKraus  
Yeah, but in that line you just quoted, it showed that their entire personality seems to be dependent on being gay.

@Mayojar77  
Best gay characters you will ever see are Gus and Wally from a show called “Mission Hill”. They’re a gay couple, yet all the jokes about them come from how laughably mismatched they are rather than just them being gay. You could seriously make one of them a woman and almost all of the jokes could go unchanged.
 
There’s even one episode where a character is wearing hot pants and another character says to Gus “Doesn’t he look gay in those pants?” and Gus replies “No. No self-respecting gay man would be caught dead in those trunks.”
 
Gus and Wally also shared the first gay male kiss ever broadcast during Prime Time. Srs.

You’re a fool Discord…and you will lose…everything!!

@DanielTepesKraus  
And that’s what made him awesome; He was a gay character who’s whole identity wasn’t built around him being gay.

And then they all shot magical laser beams at each other!

@Nightwish13  
Seriously, he actually was. Rowling said she meant him to be gay right from the get-go, but just never found a part in the book where it could pop up and wouldn’t seem like a pointless “guess what I’m gay” moment.

@Nightwish13  
Dumbledore was gay. It is canon.

@Mayojar77  
What? XD

So Discord was once Tirek’s gay teacher?