You're conflating two distinct concepts: 1) what you're obligated to agree to; 2) what you're obligated to do once we've established what you've agreed to. You

You're conflating two distinct concepts: 1) what you're obligated to agree to; 2) what you're obligated to do once we've established what you've agreed to. You're not morally obligated to agree to literally anything, but you are morally obligated to uphold your end of an agreement.