Fast approaching the end of my fifth decade, I find that I just don't memorize verses as easily as I did twenty years ago... yeesh.

So, I've started printing out lyrics to serve as my "backup". Oldtimers can really suck... lol.

But I guess what you need to do is ask yourself what it is you want to accomplish. If you want to share the experience of singing a song - then do what it takes to get the job done. Use the book, but maybe try to lean on it less and less if you can.

When I'm in performance mode, I like to make eye contact with the audience and make them part of the experience. At sessions I'll tease some of the older folks to get them joining in the chorus... at least to mouth the words. If I spaz on a line - well let's laugh it off together. If I use a sheet - then I let them know the brain ain't what it used to be & try to use it as little a possible.

If you are at a group that frowns on this, then they are the one with the problem, not you... but it still makes things a bit uncomfortable.

It takes all sorts to make the world, but that doesn't mean you have to be like everyone else or hang around where you don't feel good about it.   If the folks you sing with aren't making a fuss, then relax... but see if you can use the aids less and less. It does improve the experience for yourself.