taste of cum

I don't mind giving my bf a blowjob in the slightest. Tbh anything that turns him on turns me on so I'm all for it. I've never been with anyone else so I can't really compare what cum tastes like but his does be really salty and depending how I'm feeling I can't swallow it cause the taste isn't nice. in general i dont like salty things like i dont even use it when i cook. We've talked about it and he doesn't mind me putting it in a tissue. He drinks a fair bit of 7up but eats alot of fruit specially apples and does drink water too. Not a big drinker either. Just wondering is the salty taste normal amd what should it kinda taste like?