X ( best friend ) rant

Samantha
So over a month and a half ago my friend told me her SO of 9 yrs was texting a women he works with and when she mentioned it to him he got super defensive about it. But before all of that , he is known for talking to other women behind her back so it is not uncommon for him to do so when he enters a new job. So now he works in a new company, and he was talking to this women and supposedly helping her because nobody else wanted too. So my friend was suspicious because of past events and how he did talk to other women. Mind you my x best friend has cheated recently also but doesn't put that in the mix since her SO doesn't know. Anyways I gave her my opinion on it because they do have 2 children together, and told her you can do better if you truly feel crushed about the situation. So then that was done that day, so she went home to him that night and I guess they made up. So the following day I asked her so what happened, she got defensive and told me she isn't going to leave him and what i feel doesn't matter. Ok thats fine but you shared this with me and im just asking for a update you shouldn't get defensive with me about it, thats who you wanna be with then fine. So she threw a low blow at me and mentioned something that happened in my relationship, which is totally irrelevant because we are talking about her. So i told her what you and I do thats our choices, but theres no need to try to open old scars for me because you hurt. So we didn't speak from then until today, and i asked her how is her and her girls. She replies with a super short sentence ( usually she will write a lot but I knew something was up.) so I announced my pregnancy as well afterwards and she congratulated me, but literally all she said was congratulations. So i knew she was feeling some type of way, so I called her out on it that i dont know why she is letting my advice get to her so personally. If you share your business with me i am going to say what i feel I wont sugar coat anything. So we just ended up saying bye, but its like she is real hurt as if i am the one who fucked her man or something. What you ladies think, am i in the wrong or what. I was just trying to be a friend and tell her she deserves better if he always does this when he goes to a new job. I've learned my lesson never get involved in others peoples relationships, but if you sharingn your issues expect some opinions .