Most people from here say sir-up, however, I have a few friends who grew up here who say seer-up so that must come from their parents? One of my good friends who says seer-up says it on purpose to annoy me all the time, lol

You'd be surprise the weird local dialect we have here. Thank god I didn't pick any of that up, likely because my parents were both from elsewhere. One example is "warsh" instead of "wash". "Farty" instead of "forty". Basically adding in R's where they don't belong. It's ridiculous, and this is local STL speak only, not MO as a whole. It's an odd phenomenon. I do have a strong midwestern twang, however. At least that's what outsiders tell me.