When your bridge starts to crumble

So my post the other day was called Building Bridges...But what happens when the bridge starts to crumble?

I want my mom and Boog to get to know each other, spend time together, have a relationship...But I don't like being around her when she's been drinking, and I don't want him around either...

What do you do when you tell your two year old that you're going to Gammaw's house and you can tell he's excited...then you get there and she's been drinking...Do you just put on your big girl britches and deal with it so he can have a good time? Do you just make sure to cut out early before things go south? Or do you just say fuck it and leave as soon as you get there?

Keep in mind that this visit had been planned, only for 24 hours, but planned none the less...

I went with option B, cutting out early before things go south...and it seemed to work...I was getting irritated with her, but Boog was having a good time for the most part...

How do I bring this up to her without her freaking out and cutting off all contact with us/him again? Like I said before (http://lifehereonout.blogspot.com/2011/11/dear-abby.html), she didn't see him for a good bit of months, and the time she saw him that I mentioned that happened in July, was only for about 5 minutes out front of her house...

Anyway, thanks for reading...Open for ideas...