Foul smell

Why is it that whenever I sleep with my ex who I’ve been sexually actively with on and off since I was 15, I’m 23 now, and without fail I almost always get a yeast infection and or a bv smell. It usually starts as a yeast infection (I never get them any other time) and it’s like my vagina is raw when I wipe after there’s tiny little blood spots .. and yeah i feel like it’s a pretty bad yeast infection every time… and almost always once the yeast infection is calming down my vagina gets the worst smell either fishy or like something crawled up there and died … Why doesn’t/didnt that happen with any of my other sexual partners? And why is almost every time with him? I can think of a handle full of times that didn’t happen… do our juices just not mix? Is he dirty? I don’t wanna think he’s messing with me after doing whatever with whoever and not cleaning himself … Is there something I could do? Or we could do that prevents that? It’s gross to me

and honestly makes me not want to be intimate with him… and I don’t get why I only have this problem with him….