... do you guys usualy try to stick with your same diet throughout the rest of the day?

today im going to my grandma's house for lunch (and she makes the greatest food on Earth, no kidding ). and well it isnt too healthy, but i dont get to have her cooking very often, and ive been bulking VERY cleanly as of late. so i dont plan on "pigging-out", but i do plan on having some of the food. should i just try to keep my calories and diet pretty much the same, assuming i wont pig-out at lunch?