At the light pop Liz looks up.  Her first emotion is relief, knowing that she'll be able to get what she needs.  But then she sees the embarrassment on Cayn's face and hears Xy's words, realizing for the first time that apparently any magical seed would do.  She blushes as well, but has to agree with Cayn a bit on the appropriateness.  Xy is, for the time, her master.  And while Cayn may be teaching her magic, there's no reason why he would want to be that intimate with her.  And from her end, she'd rather continue such an endeavor with a creature she has no feelings for than one that she just possibly might.