It sounds to me that either someone’s feelings have been hurt or you are starting to feel some qualms about what passes for “friendly teasing” in your social circle. Either way, it really doesn’t matter what your intentions are. Calling people names and making fun of them, which is commonly understood to be rougher treatment than actual friendly teasing, is an inappropriate way to treat anyone (much less friends). If you don’t know the difference between friendly teasing and verbal abuse, then err on the side of caution and refrain from it completely.