Depends.
Some good answers above.
I’m with @chyna on spitting. That’s disgusting. Growing up in NY I was told that was illegal.
I would not tolerate my husband being a liar, but I know there are liars in the family and I let it slide. They lie about things I’m able to ignore, and they don’t affect my every day life.
People who are disrespectful all of the time. Who use mean language or are dismissive. Who constantly put others down.
Physical violence is another one. Although, I know some men who were physically abusive to their wives in the past and I still talk to them when in their presence.
Force feeding children is up there with making me very uncomfortable. That’s physical abuse in my opinion.
Alcoholism I can’t be around for long. I wouldn’t disown someone, but I try to draw a line.
People who are very passive aggressive. They are impossible.