I'm the friend that destroyed the friendship. (Probably the wrong place, but I really need to get this off my chest)

Me and my best friend, lets call him Mike had been best friends since middle school. When this happened we were both in our early 20's.

It's sort of a long story, but we had been both going after the same girl for a few months, eventually me and her started seeing each other. Mike handled it in stride, until a few weeks after.. I had a party at my apartment one night, it was a couple hours in when Mike showed up as soon as he got off work. I was pretty drunk at that point, and I walked into my kitchen to see him mixing a pitcher of vodka and cranberry juice. I distinctly remember thinking he was making it really heavy, so I thought it would be funny to say "good idea, that'll make my job a lot easier later". I truly meant it as a joke, without thinking about the ramifications. He didn't say anything, and just walked out of my apartment. My girlfriend got mad at me for being so insensitive, and we had a pretty major fight over it. Less than a week later I walked in on my girlfriend cheating on me, and I ended up having a mental breakdown and getting myself arrested. I haven't seen or heard from either of them or any of my friends from back then, since. It's been almost 6 years, and I still regret what I did every day.

I never thought that one sentence could effect my so much.