Honestly, one off-plan meal like that isn't really going to make any difference in your diet in the long run. Just so long as you stay on plan the rest of the day and get right back on plan afterwards, it will be but a small blip in your overall weight loss. I eat out with friends at least once or twice a month, don't worry at all about what I eat at those times, and it rarely seems to make a difference in my weight. It's when I have several off plan days at a time (when I'm on vacation and eating out for every meal, for example) that wrecks havoc on my weight.
My Before and After Pics
"Decide what you want; decide what you're willing to exchange for it; establish your priorities, and go to work." --H.L. Hunt
"Life has hills. Set the treadmill at an incline."