It's disappointing on the cock sucker's end as well. I not only LOVE how awesome cum tastes, I also love to feel a man's cock balls deep in my mouth when he unloads.
As a cock sucker, I have to agree. I not only want to taste the warm cum on my tongue, I want to feel that cock pulsing in my mouth as I drain a man's balls, it's such an erotic feeling! Back in my heyday, if a guy gave just the right verbal cues, and shot a big enough load,that alone would make me cum too, even if nobody, (myself included) was touching my cock.