Nope, as an atheist I have perfected my chameleon technique and can even say a very heart felt prayer, for to me love is their god and I have nothing against love.

No I just do not indulge and if asked to say grace I say grace the one word does it for me.

No. I'll keep an open mind to their beliefs.

Even when we host, we offer to let our family say grace. I find it's just another 30-90 seconds to anticipate the meal, and go over my mental checklist. I will even go so far as to hold hands and bow my head.

No. It intrigues me at times. "Yaaaay! I've temporarily joined this cult!"

I still go--because I like food. I'm never asked to say grace because I'm shy and I just kind of awkwardly sit there when everybody else bows their head and folds their hands.

I have been asked to say the blessing or grace a few times. If I’m ask to say grace I say “Grace in the kitchen grace in the hall goodness Grace don’t eat it all” for the blessing “Bless this food and bless this meat. Who Evers hungry come and eat”. I know it’s corny but they never ask me to say it again.

No, as long I'm not coerced to participate or chastised for not participating then I'm fine, I usually try to be respectful and be quiet while they say grace.

No I just stand there quietly and look around at everyone and occasionally make faces at the kids to try and make them laugh.

No not bothered by it. I can even give the grace.
I know I won't explode or spontaneously combust by doing it.
We say things every day that we don't mean or don't actually believe. As a paranormal investigator sometimes it calls me to use prayer and such to comfort the client. It doesn't matter that I have no faith in it. The client does and it helps me to resolve their fears.
Easy peasy.
If I gotta pretend I'm at Hogwarts to get a good meal. "Expelliarmus!".

If I have to spend the whole evening talking about god McDonald's sound like a better option.

I don't really worry about it..

No, I haven't had too but probably would

Sometimes ... Other times like reunions and birthdays I show up later. It's at someone else's home then it's their call ... A blessing would be better than grace.

Never. It is called being gracious to the host of the gathering. I think many atheists have an intolerent chip on their shoulder

The worst situation I have encountered was being asked to play Jesus for a reenactment of the last supper. It was for kids and I had a lightning rod handy. My friend requested that I pray over the meal.... I don't know how to pray! Much less make requests from guys on clouds...

I let them do their grace, I just leave the room when I can, try to not be at table and as last resort when asked why I did not join tell or remind every one how I feel

what is 'join for grace'? I am gonna have to look that up...

No. I just use the moment to express gratitude and love and allow others to do that in their way. But if it turned into some grovelling to Jesus and reminding everyone about Hell, I'd stay away too.

Not avoided gatherings, but I have avoided the table until after the prayer was said. Such B.S. thanking God for putting the food on your table.