Mandy is only protective if she thinks something/someone is trying to hurt me. But if someone just shakes my hand, it just makes her want to kiss them more, seeing that I approve.

Nova would still get them to try to play with her. I don't think she has a mean bone in her body.

Luka, well, I'm not sure really. I haven't had an instance come about to see if she would. Something tells me she would, but I'm not positive.