To touch on a few points here...
This was my MIL's wake and it was my BIL and his kids drinking. Trust me, I dont need a wake to turn around and talk about this guy.

However, I dont feel I was making fun of him at all. I was asking for opinions on the situation, mainly because as I said in my original post, I may(ok, I do) have a biased opinion on the person. Even my DH, who yes, just lost his mother, was embarrassed by what they were doing. He even said "I thought my mother raised us better than that"
And yes, the bottle was opened with a loud noise during a 2 minute prayer service. I guess he couldnt wait.
Drinking the sprite was not his only break as he also went out to the car to eat a fast food meal with his whole family. I will admit I brought snacks for my kids(4 & 7) but made them take a very quick 5 minute break outside. DH never went outside.
There was a large hallway with furniture outside the viewing room and if the drinks were kept there I wouldnt have thought much about it. Water was offered there. There was also a "smoking room", but I dont blame them for not going down there. I wouldnt have wanted my kids eating there either.
I guess according to what HusbandAlwaysWorking mentioned, I was correct in thinking the drinks werent technically allowed in there as we are in MA too.
As for the laughter and fun stories, we had lots of those, especially while looking at all the pictures. I agree that it should be a time of celebrating the person, and I know she wouldnt have wanted everyone sad. I guess the reason the drinking shocked me so much is because Ive just always known you dont do that...and maybe because, as mentioned, that is technically the law. Maybe its no so much an inappropriate thing when it is allowed, but being from a place where it isnt, made it seem wrong to me. Its just something you dont see around here and seeing it, like seeing anything different, made it stand out.