Joe, I sill don't see the problem. When I'm learning a new song I get to the point where I might need a lyric sheet just to glance at now and then, but I certainly don't read from it word for word. There's nothing wrong with that in my opinion. It sounds like something you do, and I don't think it would be considered a distraction or discourtesy in any singing group.

When I go to a sing or a jam I consider it my obligation to prepare in advance - learn the song at least so I can sing it with just occasional glances at a piece of paper, or play the tune through without any big mistakes (hopefully without any). But what I REALLY object to is people coming to the sing or jam without any preparation. That is a discourtesy to all the others in the group. That's why I object to the use of RUS in song circles - it allows people to come totally unprepared and then try to participate. I think that's what the group you were invited to wanted to avoid.

Cheers, S. in Seattle