I don't want her due to obligation - I want her because I made a promise to her (and she me) to be married till death...
bigybiz,
When I read your sentence, it seems like you're saying you don't want your wife if she feels like it's an obligation, but you want her because she made a promise (an obligation) to be married until death. So, to rewrite your sentence, this is what I read, "I don't want her due to obligation, I want her because she's obligated."
I assume what you really want is for her to love you enough that she'd want to stay with you regardless of any obligation.
