Its natural to have teacher crushes since you're young and not married. Important though not to go any further, even with flirting. Think of his wife and perhaps children - imagine being a wife with all these attractive eager young women. I don't know if this is high school but he could get into serious trouble if this went anywhere. I'm surprised he touched your waist since most schools has a no touching rule. You're not a pervert for having feelings but don't go any further