I don't think diet has as great effect on the taste of semen as one might think. I thinks it's more like some guys just tastes better than others. From "sex-talk" chats I've had with female friends over the years, I've heard stories of men's cum being everything in taste and consistency, from close to water, to as thick and nasty as Elmer's glue. Which is pretty much the range you see in porn. So, I equate it to some pussies just naturally taste better than others. Thankfully, I've had many partners who both like CIMSW and have told me that I taste good. I've also had women who wouldn't put their lips anywhere near my cock, even after I performed oral on them as often and for as long as they like. But that a different topic. lol
I don't do the SP thing so all my experience has been with civvies. I've had partners kiss me after CIM and it tasted fine. The way I look at it, women taste themselves when you kiss them after DATY or fingering them then having them lick it off, it's only fair that one reciprocates. I find both a really hot experience. Although, I have absolutely zero desire to taste another guy's cum.
My wife and I are friends with a couple who were separated at the time and were no longer having sex. We ended having threesomes with his wife and going to Oasis on occasion. Later on, I had one-on-one sex with her many times. That's when I realized how much she loved swallowing my cum. I've lost count of the number of times she blew me and swallowed my load since. One day after an amazing CIMSW, I said, I think you're addicted to this stuff. She laughed and said, if it tastes good, I can't get enough of it. lol
I think part of the reason men like CIM is because they often can't CIP without serious risks. Pregnancy, STIs etc. CIM offers a similar bareback feeling, and if she can DT like our friend can, it's an amazing feeling. My wife enjoys CIMSW but she has a gag-reflex, so when I get to blow a load down our friend's throat, it's epic!
Does diet affect the taste of semen?
https://www.medicalnewstoday.com/articles/326027#summary