mew... don't feel crappy... sometimes you just have to spit... and if for you, it's more times than not, that is really OK.
i have the luxury of knowing my husband for 15 years... so whether or not i swallow, is really beside the point in our relationship now...
there are a lot of reasons why people can and can't swallow... people have different body chemistry... sometimes, just becuase, your stomach may be "weaker" than others...
like suivko said above, sometimes if it hits the back of your throat too hard, it can set off a gag reflex and no matter how much you want to... swallowing is not an option...
if you want to try other options that make you feel "less bad"... try being playful when you spit.
i have a girlfriend who simply CANNOT swallow... like you, she said she would nearly hurl everytime she tried to.
now... she spits her mouthful into her husbands bellybutton when all finished... then she kisses her way up his tummy and chest until she reaches his lips...
he loves it... and is not offended AT ALL!
the key here is... whatever works for you and your partner is what is best... don't let anyone else's preconceived idea's of what "should be" dictate how you feel...
~ springrain