This. I mean, after cumming you pretty much lose all sexual arousal, making the idea pretty pointless since the pleasure in it is gone. I mean, sure, I'd swallow if I'd sucked a guy off. But my own? Pointless.
I love it while I masturbate it gets me more aroused. I fanaticize that I'm tasting a hot ass guys cum. It makes me crazy. It makes masturbating more fun for me.
Nothing wrong with it. First happened to me when I accidentally shot it into my mouth. If you expect a girl to do it for you, you shouldn't be so afraid of the stuff.