Watching the train wreck.....

So I have this neighbor, "Sarah." She is not very happily married. She is always saying her husband is a dick.(I sometimes agree with her!) They seem to be constantly not getting along.

While I am at work I get a text from her to see if I am going out? I text back, I am at work, don't leave until 11:30pm. Then I ask if she is going?

She text me that she is out with her husband, she has had to much to drink, and he is being a dick! At this time its about 930pm.

Around 11:00 again, she wants to know if I'm going out, via text. Again, I'm still at work.

I text, "Are you out?"
She replies that she is w/ a shhhh....!

I text: who are you with?
Sarah: my girlfriend
I text: FUN!!

So I had to stay a bit late at work. I got home at midnight. I look to see if she is home. I see her and her girlfriend in her driveway. So I think to myself..I'll get my bags out of the car and then say hi.

I walk to the end of the driveway...They are running into her neighbors house!! Now a little back ground about Sarah and her neighbor....

"Sarah" and "Tim" are next door neighbors. Tim is divorced, lives alone, has a girlfriend who is married. The girlfriend comes over in the afternoons. Sarah likes to call her the "afternoon delight!" Now I have always noticed the chemistry between Sarah and Tim. So have a few others. I know for certain the two of them have kissed. Beyond that is pure speculation? But who just kisses??

I know she is not happy. Its just not always that easy to leave a relationship when you have kids involved. I know she wants to leave, she has said it herself. I just feel like I am watching this train from across the street, I can see the wreck comming and if I say anything to stop it I will be the bad guy?