Telling someone I'm undetectable

Been dating this guy for a couple of weeks. We have been getting along real well and he tells me he had a crush for me for a year or so. We took this trip this weekend and everything clicked. He was so happy and kept telling me how happy and excited he was about us. I haven't told him yet I was undetectable I wanted to see where things went. We haven't had sex because​ i really like him and didn't just want it to be a hook up . I told him I wanted to talk to him in the next few days because there was something i wanted to tell him. I didn't think he would care but he said that he needed to talk to me too but just didn't find the time too. A friend of time hung out with him and he told my friend that he heard I was + and with aids (I'm not) and friend told me he didn't take it so well. Now my plan of telling him kinda switched and I don't know how to start now. Any suggestions?