Both are bad, aren't they?

1. I see this as manipulation and taking advantage of someone
2. Are they saying bad things to you? Or are they saying bad things about you to other people? If they say bad things about you to others then it is the same as #1. If they say bad things to you directly, then it's ingratitude.

I'd probably dislike #1 more than #2. With #2 you might get upset, angry but at least you know the person and if you continue to do things for them then it is up to you or maybe you still do things for them because you know that it is the right thing to do regardless of how they behave.

With #1, you are getting manipulated, they take advantage of you without you knowing, they hide their real intention from you, others might know but not you. Then when you discover it, you feel stupid. It might have been happening for a very long time without you knowing.