Hey everyone I'm having an issue and I don't know what is causing it. I used to use my nuk 5 every night for a long time. I stopped for a week or two because my lips were chapped for some reason and it was making it worse. Anyway, ever since when I use it over night it seems to irritate the tubercle of the upper lip. Which is the fleshy part in the center. It gets sensitive almost like it is chapped or raw. Ive never had this problem before. I've tried boiling it and sanitizing it incase there was an irritant or something on it. I'm not sure what to do, but I'm so used to using it all the time, I don't know what to do. Anyone have any ideas?