oral sex

I've been going out with this guy and last night we started fooling around in his parents car, kissing and touching each other, he started fingering me and I got really wet. He's a really good kisser? and he was hard as a rock, it was sticking out under his pants. I really like giving head and so I started giving him a bj while he still fingered me. OMG!? he came right in my mouth without letting me know that he was going to cum! and I swallowed it, not knowing what to do with it all. What a surprise? Shouldn't he have told that he was going to? Anyone else have that happen to them? Cum tastes weird doesn't it! lol