For me the eroticism of sucking a guys cock and having him orgasm is exciting. His cock twitching and spasming when he shoots his cum is exciting know what he is experiencing. I’ve not tasted a bad load yet. I guess I get caught up in the moment.
I'm like you, I haven't tasted anyone's cum, but my own and I think mine is delicious!!! My precum is a lot sweeter and much more "tasty", but my cum is still good!!!
I have those fantasies quite often myself because of the fact that when I was much, much younger I could actually suck my own cock. So I know what it feels like to have my "throbbing cock" cum in my mouth and I loved it. I know I'm not limber enough to ever do it again so I fantasize about other cocks!!
I'm like you, I enjoy having the opportunity to make him cum and never focus on the taste of his cum. I've rarely said a word about the taste of a man's load of cum unless it was a very sweet tasting load, that kind I want three or four times a day.
From the moment the first opportunity presented itself, I felt an overwhelming desire to suck cock, and from that very first time I desperately wanted to take his load in my mouth. To me, semen isn't "gross", it's almost mystically sacred; the distillation of his life energy. That moment of communion incorporating him into my body fulfills some primal need deep within me like nothing else does...but that's just me. Personally, I revel in it, but like good whisky, semen can be an acquired taste. You can either continue to swallow and accustom yourself to the flavor, or not; lots of people will suck cock without swallowing; at the last moment they'll pull out; jacking you off until you cum in their hands. If you gagged, sputtered, and spit, it's likely (if your mate's a good human) that the next time you go down on him, he'll be a gentleman and give you fair warning before he ejaculates, but it's your responsibility to set personal boundaries and communicate what you like and what you're willing to do.