I began recently going to live SA meetings and one night last week my manager at work shows up to the meeting (it seems he's a regular).
I was very intimidated by this manager before I even met him at SA but now it became excruciatingly awkward!!!
Whenever I interact with him at work its like there is this huge elephant in the room (the secret that we both share) that we aren't discussing...

I am very shy in general and don't know if I should discuss with him at work the fact that he goes to SA etc...
What do you guys think???

I guess it depends on your relationship
if you think your boss is someone you could really talk to perhaps discussing out of the office could really create a real bond between the two of you and you could help each other
on the other hand if you think he may use this as a reason to put you down or avoid you then likely not a good idea

He's sort of in between....

It sounds great to me. You have a way of bonding with your boss. If you would both be golf players you could play with him and let him win. I hope he has more sobriety than you and doesn't fall! I would speak to him about SA only in the meeting room and not at work. An added bonus is if he hires a triggery girl, he will be more inclined to enforce dress rules.

Hatzlocho!