<human>: Can you succinctly summarize the text in 1-3 sentences?

To make long story short(ish), my best friend "Amy" broke up with "Mark" four years ago. About 1.5 year ago they had a one-night stand "for old times' sake." She got pregnant. They got engaged. I didn't like the guy when they were dating, and I told her candidly before the wedding that I thought she was making a mistake. She was a little upset with me for saying that, but we remained best friends after the wedding.

It's been less than a year since they married, and all the bad habits and personality traits that made her break up with him the first time are driving her crazy again. I won't get into them all; suffice it to say that he's basically a man-child who has no concept of sharing responsibilities or respecting the needs/time/requests of Amy. 

I won't say "I told you so" because that's unhelpful and petty. But when she complains to me, I don't know what to say. His poor behavior and irresponsibility were the reasons she broke up with him the first time. I generally just say "I'm really sorry he's acting this way, Amy." I've thought of talking to Mark directly and telling him he needs to get his shit together, but I don't want to go behind Amy's back in her own marriage. That said, she really does deserve better. I can't believe the shit she lets him get away with in their relationship, but it's starting to grate on her. I want them to stay together for the sake of their baby – I want him to man the fuck up and be a responsible parent and partner for my best friend. But in the mean time, do I just sit across from Amy and make sympathetic noises as she tells me all about his latest crappy behavior? I've already brought up the idea of couples therapy but they can't afford it. I think if it came down to therapy or a divorce they would find the money, but at this point I don't think it's on the table.
<bot>: best friend married a guy we already knew was sub-par and now she constantly complains about him. I want to be supportive but I'm not sure what to say.