Prom is pretty much the high of the year for them. So no, you are not going to spare everybody by canceling it. And kissing lesbians is as erotic or not as any couple kissing; it depends entirely on the perspective of the onlooker. So if that is even a reason for a decision to cancel the event because some couple might start kissing (nevermind now whether or not the couple is lesbian) means the school board should “grow up and get over it”.