Should I apologize for what I said or what should I do?

At school today, we were doing a lab and the teacher wasn't in the room. Then all of a sudden I smelled something really gross and I jokingly was like "ewww who farted?" Then these two nasty 's I can't stand were like "Your so immature" Mind you they talk really loudly about really stupid stuff, and act like they're 5. I told them that they were the immature ones because they talk really loudly and stuff like that and they were like "no you should just stop eavesdropping." I told them how was I eavesdropping when you just talk really loudly. I also told them that I didn't care if I was immature then again they were like, "no your in high school grow up." It really pissed me off, but had a really hard time not showing it. I tried apologizing one of them but they said "ick" to me. I don't want anyone to be mad at me..but again It really pissed me off, and wanted to smash them. I've disliked them since the day I met them because of their immaturity, and their rudeness. Also they have a thing for making stuff up about people..I don't know what to do, should I apologize and just ignore them if they make up stuff about me, or what should I do? PS- Yes I know I was immature about the farting thing but still.