My friend read private messages between me and their partner and is extremely upset.
I have been friends with both parties for 5 years, I considered myself extremely close with my friend but also friends with their partner, a few months ago my friend was clearly unhappy in their relationship and announced that they were having an affair, it was worded very vaguely so I don't know what level of physical it was and made it clear that I did not want to know because I was friends with both parties, they then backtracked and said it wasn't physical.
My friend works long hours whilst partner looks after the children, I started to notice friend making out that partner was terrible to be around when talking to others, wanting more time with friend, being stressed all the time and asking for more help with the children, not doing enough housework, being grumpy about friend attending so many work events etc, it didn't quite reflect what I was seeing but I don't know what goes on behind closed doors.
During this time I got pregnant and withdrew, I had a really rough and scary time and barely heard from friend, but partner stayed in touch, they separated and things stayed amicable for a while but it got pretty messy, friend is saying they've been kicked out, partner is saying they haven't at all just asked not to sleep in bed together, partner has no idea what to do about finances as everything is in friends name, friend is sleeping at work and threatening 50/50 custody when this isn't feasible due to work.
Meanwhile friend is now with the person they were having an affair with but not telling partner this is the case.
A few weeks ago I was seriously ill and partner rushed me into hospital, I didn't hear anything from friend, not a peep, I nearly died and my friend was silent.
This resulted in me venting over messages with partner as we've both been hurt in different ways by friend, they weren't nice to read so when friend messaged me a string of bizarre justifications I knew they'd read them and they are very hurt.
AIBU that I actually don't care, when explaining that their actions had hurt me I just got more explanations as to why and how terrible friend had it.