My ex and my manager.... SLEEPING TOGETHER?!

My ex (who I hate to admit I still have feelings for) was a dick to me. It ended. But the thing is, we work together. His family own the company that we are at so he's got a high status by default. Anyway, this new manager joined about 3 months ago. She's in a higher rank than I am and she's older than me and my ex - she's older than my ex by about 4-5 years...

Anyway I noticed a couple weeks ago that they're getting kinda close. My manager is married with kids so I thought nothing much of it. But then I noticed they're kinda flirty and they're always sitting real close to each other in the office (like so close that I've seen their legs intertwined) and then today I was in the office and my exes phone went off nearby and it was within my eyesight so I had a little look. I saw messages from my manager texting him. They seemed like flirty messages. Lots of emojis and just not "work related" texts I could expect to see. I also heard my ex on the phone in his office and he shut the door so no one could hear. I see my ex everyday and I know him anyway and lately he's glued to his phone; then I've seen these texts and I guess I know why now. I don't know what to do or how to act. Like I said, both these people are of a higher status than I am. I always thought they had a thing for each other but I never worried because my manager is married and has children. I need to know I'm not just going crazing here! There's no one I can talk to about it at work because they all LOVE my manager they think she's amazing and of course they wouldn't comment anyway. I guess I just need support and advice.. Please help! 😥