How do I tell my boyfriend I’m allergic to latex condoms?


So I’m 17 and in my life time I have slept with now 3 men and all have used condoms. And after each time I notice an allergic reaction. Recently my new boyfriend (#3) and I had sex with a condom and I totally forgot to tell him I was allergic to latex. How do I tell him without being rude or having him think that I just want him raw?