Smells during oral

Hi, when my partner and i do specifically face sitting, he has mentioned to me that he doesn't want to do it because he said it's smell like crap.

I wipe, I shower and take care of all my bits with soap, make sure the hair is trimmed, etc. and over all, i try my absolute hardest to be a clean person. I tried looking up if this was a common issue or how to address it, etc. And the most i could find was someone saying ass is always going to smell like ass not flowers.

The only thing I can think of is to shower before we do this each time, or start carrying wet wipes with me and see if that makes a difference.

I feel embarrassed and a bit frustrated because I'm not a dirty person. I also don't know what has changed because this never used to be an issue. Or the bare minimum he hadn't told me about it because I used to think he really enjoyed it too.

Edit : Just to try and address some of the comments and add relevant things, i forgot to say.

1. He is on the asexual spectrum, not all the way to one side or the other. With this said, i have never forced him or pushed him to do something. A no is a no. We allow each other every few months to check back in on an answer, but it's never a push or guilt thing. I haven't received oral since he said this. (Which is okay), but I want to know how to address the issue or see if it was common or etc.

2. I have gained weight, but I'm not overweight in 5 10 and 170lbs. It all went to my thighs and ass.

3. I use soap to clean my bits. I don't shove soap up any holes just around the outside. As well as a honey ph balancing foam again only on the outside.

4. After reading the comments, most were helpful, and I really do thank you all for taking the time to respond and help me figure this out. I will be trying to take some of the advice such as the toilet attachment, unscented wipes, diet, etc. I will say for the people who commented a touch more negatively about the showering beforehand with sex in general and how it needs to be more normalized, etc. I get where you're coming from. When I was new to sex I always showered beforehand and had him too. Truthfully, though, unless one of us had a really hot day and it's sweaty and really stinky because of it, i don't push it as much. One or both of us has lost the mood that way before, and sometimes spontaneous things are just nice. I do see and know where you're coming from, but so long as you are in general a clean person and not giving your partner diseases, i figure to each their own.

5. Typically, when I would face sit, it was the direction one would be in when doing 69, so I do acknowledge his nose is right in my business.

6. I've only ever had 1 other sexual partner, and he never had issues eating me out and tended to enjoy it more than me.

7. Last thing to address, i think if not, I'll come back later. The conclusion im drawing from all the comments is be prepared try new thing's to address this possible hygiene blip but if it doesn't change much it may just be that I'm a human and we don't naturally smell like flowers and candy. And it may just be something he's not a fan of doing, which is okay.

I really, really, really do appreciate all the comments and help you have all given me. And I appreciate most of you not making me feel like I'm gross because I do really try to be clean, especially if someone is going to be all up in my business.