Eat what you want to eat and enjoy yourself. If you actually don’t want to eat something don’t, but if you do…do. Enjoy your reunion. Have a glucose disposal agent like Dihydroberberine, maybe some digestive enzymes which are always helpful regardless.
Keto is a WOE, not a religion. There’s also the point where it can become unhealthy, like when months in advance you’re stressing about a meal, that’s when you know your relationship with food is just as unhealthy as when we were all carb junkies, just in the other direction.
You eat keto all the time, you’re more or less glycogen depleted, or at least running on a very small supply. One meal isn’t going to totally reload your liver glycogen, muscle glycogen, and start spilling over. So your blood sugar will be high for a few hours, so? It’ll come back down.
Allowing yourself to become Orthorexic doesn’t lead to enjoying yourself. Regardless of WOE, everybody eats a crappy meal sometimes, whatever their WOE, it’s a crappy mean for them. You eat, enjoy, and move on. Doesn’t mean binge or be crazy. But don’t stress about food either.
Then there’s also the math, even if still insulin resistant, Mexican is typically higher in carbs, which will cause more of an insulin spike than normal, which in that context is a good thing, because it’ll drive it back down faster than a small or moderate amount would.
Don’t forget, physiological insulin resistance is real in a keto’r. We deal with larger amounts of carbs better than we do smaller ones because of that. The difference is we just can keep doing that over and over, that hyper reaction in that case is a positive one, not a negative. Plus, your next workout will be awesome!