My (18M) Parents (50F, 49M) Are Blatantly Being Unfaithful

I know both my parents are in love with other people but I haven’t seen any indication separation or divorce is coming.

My mother (50) is constantly talking to or about another man called Patrick who used to live across the street from us; we moved a few miles away but he comes around often and she goes to visit his house as well. She knows a lot about his life and how he’s always right about everything.

My father (49) is in love with a woman he works with named Susa. Calling it anything other than what it is would be silly because I’ve been in their office building and one of them is constantly in the other’s cubicle area, whispering and laughing and and putting their hands on each other. I also distinctly remember more than one occasion when Susa came to see my father at our house late after work and went behind his door for at least an hour while they were discussing “budgeting.” Yeah…..

I’m sad of course, but also I guess I’m just really confused why this has been going on for at least like one year and it seems nobody’s doing anything about it. Wouldn’t my parents be wanting their own place if they love other people so much but are borderline incapable of communicating with each other without having some sort of argument about any number of stupid issues?!

I’m not stupid, I’ve had romantic relationships of my own. I know they can be difficult! My friend Max and I basically didn’t ever talk for a month because we were both in love with one girl. I’ve had one relationship end by text message! If my parents don’t like each other and want sex with other people, why force me to suffer and pretend how none of this is happening?

Every night, I dread having dinner with both of them cuz if one of them ever brings up their “friend”, I know damn sure the other one will insult the other very badly and ignore me completely. It’s also common for them to just get in some stupid argument anyway, sometimes about me!

If I’m honest, I would say my father is the one who’s actually having a more physical romance, while my mother’s relationship seems to be more of an emotional one. But hey, it’s always possible I am completely wrong!

I don’t have any clue about who to talk to about any of this except here, because I can be anonymous. All these names are made up. I am 18 years old and absolutely boxed in. I have 1 sister (22) in college and we don’t really discuss this very much. Is it something I should let her know about?

TL;DR I know both parents cheating on each other. Can’t move out. Should I try anyway? Should I tell them? Should I do anything about it? How can I cope?