Yeast Infection? Boyfriend keeps getting Balanitis. Help!

Hi! I (37F) need some help as this is starting to be very annoying and doctors dont seem to help. I'm having some vaginal discharge that i would say is not lumpy like cottage cheese but is white and speckled, this has been going on for at least since my boyfriend (40M) and I have started sleeping together about 6months ago. I have had yeast infections in the past but generally after some OTC stuff it goes away and isnt much of a problem.

Unfortunately, my current boyfriend keeps getting Balanitis when having unprotected sex. The first time I thought this was not a big deal and took some OTC medication to make sure I didnt have anything but it has become an ongoing issue that we're not sure if we're passing back and forth. We've tried to rectify and take medications while sticking to condoms temporarily but almost everytime we have unprotected sex he gets balanitis (or most recently the skin on the end of his penis peeled off to leave more tender skin). He has diabetes so is sensitive to yeast from what I understand and we've attempted to be diligent by ensuring we shower after sex.

I've also done yeast and trich tests, they've come back negative the last 2 times. I did have a test come back positive for BV but the last test i did a couple of weeks ago also came back negative (along with the yeast and trich), even though he had balanitis at the time.

I'm not itchy. I would say there is a smell I notice during sex on occasions but it is not fishy and I wasnt sure if its the latex. I wear no underwear, wash my vagina (outside but along the lips, not inside) with mild soap daily and have a healthy lifestyle.

I do have HPV currently (he is aware) but cannot think of anything else that could affect it.

Why is my boyfriend getting balanitis when we have unprotected sex? FWIW we are monogamous. What else could be causing this, what could i have? what else should i test for? Any and all help appreciated, just trying to get to the bottom of this so we both can have some healthy bits. Sigh, and thanks in advance