onion tits????

hey gals! this is a super embarrassing question so please be nice 🥲 also i’m going to be VERY blunt.

so sometimes when my fiancé like licks and sucks my nipples (sorry for being so graphic) and he kisses me after, for some reason his breath suddenly smells like onion? i don’t know if it tastes like onion to him though (im way too embarrassed to ask) um wtf?? am i dying? keep in mind, i’m very hygienic and my skin is clean. i’m wondering if its like the milk ducts or whatever? i am not super educated on my own anatomy sorry. but please let me know if you have any ideas. i’m getting married in a few months and i want our actual wedding night to be perfect.

thanks:)