If you really can't see him tonight because your angry or just not in a good place emotionally, don't. I know your MIL thinks it would be good and all and I respect her wisdom. Perhaps you will be able to at some point. Don't beat yourself up if it isn't tonight.
When my H first moved out we could at least talk about D's some. Then as things came up, I would see him getting angry and shutting down. He hasn't asked me anything about D's in so long, I can't remember when it was. I do tell him some things. Honestly though, at this point, he can talk about anything with them. You don't have that luxury yet though.
The friend thing is really complicated and esp hard as most LBS's still have an emotional attachment (ie: still in love with spouse). Give yourself time to figure outr what you want with regards to bing friends. You can be perfectly friendly, without being friends if that's what you choose.
