I’d say you’re DD this year and fake a drink. Idk how health conscious you are or what your drink of choice is but you could bring a bottle of something to “mix” with soda. I’m assuming nobody is gonna ask to taste your rum and Coke or vodka soda. As Sheldon would say, just make yourself a virgin Cuba libre and none are the wiser except you will have to get creative with disposing of the shots. I would avoid saying you feel sick. You’ll get called out fast lol. I also tried the I’m on this medication and was called out/outed with coworkers. The funny thing being I was supposed to start that medication and my doctor did tell me she wanted me dry until the found the right dosage, but I decided against it because I was newly pregnant and I didn’t feel comfortable taking it when I could manage without it. I tell family and friends pretty much as soon as I read positive. I don’t have a good poker face. So I don’t have any great suggestions unless you’re good with close up magic. Oh! Maybe do the Coyote Ugly spit it out trick? If you’re doing shots, pour a chaser. Then when you chase it, just discreetly spit the shot into your chaser instead. Repeat for back to back shots or conveniently set your cup down and lose it. Idk how big the bbq is but if it’s like how my friends bbq then people are gonna be too preoccupied to even notice. But I think you bring a bottle, it could be a good subtle misdirect. Just play it cool if someone asks because I’ve been asked so many times if I was preggo when I was just being introverted lol so mentally prepare your comeback