Yeah, the sex is the hook for bait this sex demon into a relationship. Just like you can’t catch a fish without the worm, you can’t catch a Kas without the sex. 
Really, it’s not the issue of PC being interested in Kas, It’s a matter of Kas being interested in PC and she’s not interested unless you bang her somewhere.
Really, it’s not the issue of PC being interested in Kas, It’s a matter of Kas being interested in PC and she’s not interested unless you bang her somewhere.