Is it normal? No. But it's not unheard of.
Words like "slut" or "whore" are, of course, universally shunned in civil society. But that's where the appeal is for some guys. They know those words are hurtful (and thus powerful), and that knowledge turns them into forbidden fruit. And we all know that forbidden fruit is often the most enticing.
Using these words are part of your sexual relationship, and like all things in a healthy sexual relationship, both parties need to consent to them. If you don't mind being called those words, then it is perfectly fine for him to call you them. Just as if it would be perfectly fine for him to tie you up or whip you with a belt if that is what you wanted.
But if you are offended by what he says or think he is demeaning you, you need to tell him. If you want those words to be off limits, they are off limits. And him continuing to call you those words would be grounds for a breakup.
In short, those words are offensive. But if you want them to be a part of your sex life, they can be. The power, and the choice, is yours.
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My boyfriend's done it a few times, of course if he tried it in a non-sexual setting he wouldn't get away with it, but sometimes it's cool to play a bit with possessiveness and being treated like a sexy sex object. And maybe highlighting the whole 'lady in the parlour, wench in the bedroom' thing a bit is exciting to him.
But it only really works if you feel comfortable with it so yeah, if he's over-doing it let him know. Or start calling him those words in return!
my boyfriend does the same thing to me, and he actually asks me to call myself his little slut. I don't find it demeaning because I know how much he respects and loves me. Its purely a sexual thing and since we talk dirty a lot it helps keeps things spicy for both of us. However, if you don't like it, say something. If he truly respects you he'll understand why you don't like it and will probably stop. all in all, he should be fine.