<human>: Can you give me the gist of the text in a nutshell?

One of my best friends, Katie, has been with her boyfriend Marcus for about 1.5 years.  My husband and I know Marcus solely through Katie, for what that's worth.  My husband and Marcus have gotten somewhat close in this time though, and get along very well.

Yesterday my husband and Marcus were texting and, seemingly out of nowhere (my husband showed me the texts) Marcus went off about Katie. I don't recall now if they were making future plans or what, but Marcus said something to the effect of, "if I'm even still around then.  I don't know how much longer we're going to last." and went on to talk about how lazy Katie is, about how if she had it her way she wouldn't work, just stay home and smoke pot, etc etc.   My husband suggested talking to her about it and he said he had, many times.

Katie loves this guy, they live together, have talked about marriage, etc.  So far as I knew their relationship was perfectly fine, we just spent NYE with them and nothing seemed out of the ordinary - then these texts came yesterday.  Do I say anything about the texts, or stay out of it??  I have no idea if they were just venting, or possibly intended as a way of getting my intervention?  

I'm not sure what further context to provide, I'm happy to answer questions.
<bot>: Friend's boyfriend texted my husband about being unhappy in the relationship, and possibly leaving.  Do I say something or stay out of it?