Sex is absolutely determined by Chromosomes, and people on your side are definitely saying men can become women.. that's the main sticking point.. instead of saying "Men can act feminine, and dress like females" they are literally saying men can become female at will.. which we can all agree is 100% wrong.
none of them claim a male can become female - Chromosomes and DNA are not interchangeable, and do not allow any real change be made, all trans gendered are nothing but mimics.. nothing more.