My cum..

My boyfriend just sent me this text and idk what to say i got defensive bc idk how to fix it.. I didn't realize it was a problem.. I'm really butthurt. Can y'all give me any advice to what i should say to him or tell him?¿? "It's about your Vagina like when I'm eating it has like a sour taste I looked  it up they said it could be from wearing tight clothing all the time,  birth control pills, or lack of drinking plenty of water ,sweating or it could just be the cum idk l like your vagina its just the taste is disturbing but they said sometimes it's normal"