I wish I knew of a surefire way. I think men should all have a little switch behind their necks where we could select our favorite flavor. Just the thought of chocolate-cherry cum really gets me going! That being said, I've heard all kinds of things can change the taste: drinking pineapple juice, taking zinc, cutting out refined sugars, consuming a tablespoon of raw honey every day...I think you should just experiment. Have a taste test. If you try lots of things and you're still not loving the taste, I would suggest taking control as he's ejaculating and having it end up on your cheeks, lips and chin. Even if you're not swallowing, that's a very erotic sight. I'm sure he won't complain.
Image: Suat Eman.