[Update] Saw my roommate's [30m] ex [29f] leaving my other roommate's [31m] bedroom. Say something? Mind my business?

https://www.reddit.com/r/relationshi...aving_my_other
Last post didn't get much attention but the update is kinda of funny so enjoy:
Last post was pretty much this:
John and Kate dated pretty casually for a couple years. Greg is John's and my roommate. I saw Kate leaving Greg's room one night after seeing them outside talking once while John was gone. Greg will leave on mysterious "walks" which is out of character and not suited to our neighborhood. Wondered if I should say anything to John or mention it to Greg and/or Kate, and decided against it for the time being.
Saturday night I had a weekend trip cut short. I came home to Kate and Greg's cars in the driveway and John's was gone. I held my breath a bit and even circled the block worried I was gonna walk into a scene I didn't want to know about. When I walked in, no one was home, which was weird but better than I expected. I settled in and hopped in the shower and put on a movie in the living room because I was extremely curious at this point about what was going on.
Too bad though, I passed out before anyone got back but woke up to "shh shhh she's sleeping" and drunken giggles. It was more than two people but the way the house is set up it was impossible for me to see who all showed up. It was definitely at least Greg and Kate though.
I wait a bit and then go to my room and see Greg's bedroom door is open but empty. John's door is closed and there is light and TV noise coming from it. I peek outside and his car is there. I gave up on trying to figure it out for the night and went to bed.
The next morning I'm up early with my door open. I see Kate leave Greg's room and say hi. She acts totally normal, asking if I'm feeling better (I sent them a courtesy text that I was home), asking about weekend plans and work stuff. She goes to the bathroom and Greg leaves his room. He comes by my door and I must have had a look on my face because he just smiled and shrugged. Obviously whatever is going on is somewhat out in the open so whatever. They go downstairs to the kitchen and out comes John from his room, followed by a woman I met a few times who is friends with Kate. I ask if they had fun last night and he says he's sorry if I heard anything weird. I say I didn't, since I didn't, and they proceed down the stairs, too. Idk what I was thinking but I still braced myself for drama though it didn't seem like anyone was hiding anything.
The ladies leave and I ask Greg and John point blank what is going on. They get kind of sheepish but it comes out that Greg's been hooking up with Kate since June and Kate set John up with her friend and they ended up all in bed together last night. I bust out laughing because it was unexpected but not wholly shocking. Later that night Greg goes on one of his walks and I asked him what the deal is with that. Well apparently he buys weed from Kate that she picks up at the dispensary because he's paranoid about having his ID on file because he works a government job. I asked why she doesn't just come in like a normal person and he claims they just like to enjoy a bit of private time to make out and talk without anyone else around, which is fair because the house is rarely empty.
So. Nothing scandalous. Just some consensual Non-monogamy and some legally gray area weed exchange. Better than expected.
tl;dr they're all just ****ing each other and selling weed. Crisis and drama averted.


Source.