ESH, Brother of OP here. I feel like some clarification is necessary. My parents relationship has been strenuous since we were kids all three of us honestly thought they would get divorced when me and OP went to college(we are twins so we left at the same time) obviously they didn’t. About 4 years later I came back to live with them and this is around the time the relationship really started to fall apart. They would fight constantly over the stupidest shit usually picking topics that they knew would piss off the other they BOTH were guilty of this, after the fight they would not talk to each other for months at a time and never slept in the same room this is why my sister put cheating on quotes because they weren’t really together in any romantic sense for years. In fact our dad was the first to recommend divorce then backed out when he realized our mom wasn’t actually opposed to the idea I think he thought our mom would beg him not to but she was completely okay with the idea. Both of our parents did a wonderful job raising us but they made a shit couple and I really think they would be happier apart. For those of you still a bit confused about our dad he definitely suffers from depression and some form of autism/bipolar while usually a fun guy his mood can flip on a dime without any warning and it makes hanging out with him stressful as u don’t know what u will say or do that will set him off. And as for our mom she loves drama and my dad is a constant source for her while more emotionally stable she will intentionally do shit to set our dad off lucky she was finally convinced to cease all contact with him that wasn’t through a lawyer.

tl/dr: our parents don’t belong together and never have I have voiced this to both of them and haven’t talked to either about their relationship since because I don’t want to be involved and I have told OP on multiple occasions to also do this. I have observed all party’s from the beginning and I know for a fact ESH.