The most embarassed thing you did/do related to Mass Effect?
I must confess this game makes me do things I never did for any other.
So to say a few:
I started reading fanfic...
There were nights I couldn't sleep because I was worried too much about my crew and it's safety (never an honest problem)
I smashed a glass to the ground (twice)
I cried a few times because I couldn't take everyone in my missions, I had to choose and it made feel bad.
I can keep going all day, but I think you see what I mean.
Maybe these things are not too much for you, but It's a lot coming from me (?).