So, the guy I live with has been a friend for 3 years or so. My ex of 5 years cheated on me, so I moved out of my place with her and in with him. This was back about 7 mo. ago.

Ex and I share lots of mutual friends.

Roommate was drinking for about 12 hours today watching football with a lot of our social circle and posts up a snapchat story (any of his friends can view it) of he and my ex (completely shit faced) together eating food about an hour ago.

What the fuck? I understand the girl is mutual friends and is going to be around, but private drunken eating with my ex and then posting it up as a video like that? Granted, it's showing how entirely trashed the girl is, and it's not like a romantic video clip but why even break bread with this bitch? Why then announce to all of your friends, including me, that you're out with your roommates drunk ex? I'm really pretty pissed off here.

He's home now and the first thing he did was to knock on my bedroom door. I was sleeping, he woke me up, but I didn't answer. I woke up, checked my phone, saw the Snap, went to go see what's up but he's now totally passed out now. Interesting fact here too. He passed out with his phone face up on his chest. When I went to go see him, his phone receive a text from her, "I'm boredddddd"

I've got to live with this guy, but I also feel like I need to let him know that we're going to have a major problem if he and my ex are going to have more than just a casual relationship. It's bad enough she fucked her coworker and broke my heart. Now I've got to feel like she's gaming my roommate or vice versa. How do you guys think I should approach this? I was really working hard to get over my Oneitis and this is a major setback. I doubt I'll be sleeping tonight.

Your advice is appreciated, bros.

UPDATE: Roommate just woke up. Asked me what time he got in an claims he remembers nothing from his night (I didn't confront him on anything). I told him that he was updating the world throughout his entire day on Snapchat. I pulled up his Story on there and he just laughed through the entire thing, including the portion where he's eating with my ex. I didn't react and he's amused. He's been on his phone and hasn't brought up the text I saw come through... For now, I'm going to remain non-reactive but I'm definitely keeping my eye on this situation. I really appreciate the advice many have given me here. My group of friends is large and gossipy--if something happened, there's a high likelihood that I'll hear about it from someone else (my buddies told me when the ex was on Tinder, they told me when they saw her leave a bar a few weeks ago with a dude and go to his place, etc. If anything went down, people will absolutely gossip and someone will come to me in confidence to report--I'm pretty sure of this).

My thought, based on timing of events, etc. is that they stayed at the bar until the end of last night's late football game, then went to drunk eat. Based on when the Story video was posted, I think he posted it immediately after taking it and came right now. My guess is that SHE probably asked him to come up to her apartment and he took a cab back instead. She felt rejected and text him to see if he'd reply. Yes, I know I'm Hamstering. Who knows what will happen next... My plan here is to remain non-reactive and hold my best frame. Any additional advice is appreciated, but this isn't as easy as "this guy is now dead to you." I live with him and just moved into this place, I can't keep running from my problems.