You'd rather die than stop hating each other, but you'd actually die without each other.

He's your best friend / worst enemy. The kind of friends who swear on their lives they aren't for anyone, especially each other, then start seducing each other, flirt nonstop, then are trying to kill each other and swear death upon each other the next second? Yeah, that's you guys to a T. But, very much in theme, you're both way too stubborn to even consider acknowledging that, let alone admitting it.

You invited him over to your house to hang out (or have an all out brawl, whichever is more convenient at the time) and it started off like normal. You exchanged a casual greeting, told each other to off and that there was nothing worse than being in the same room as each other, flirted with each other so hard you might as well have fucked, and are now currently sitting on your couch waiting to see who's going to strike first.