If your marriage partner is motivated by lust and demands, do you have to sleep with him/her?
Should they not be denied to build some discipline in them and conquer their lust?
Surely to consent under this circuмstance would drag down the other into their sins?
Yes, you do.
It's not up to you to "discipline them" like you would a child. You can discuss it with them, you can suggest -- but it's up to them.
The marriage debt is the marriage debt. Vowing (on one's wedding day) to give your spouse exclusive rights over your body is...just what it sounds like.
That is what's involved with
Catholic marriage, by the way.
The marriage debt is a
grave obligation, binding under pain of
mortal sin.
No matter how many TV shows and modern-day pagans live and believe otherwise, joke about "she's gonna cut you off if you buy that boat...", "if you don't buy her a birthday gift you'll be sleeping on the couch", etc., it doesn't change the truth or the reality.
I gather that priests have to worry about this a lot in the confessional. It's one of those reasons why priests are often grateful for their vocation, after listening to X number of confessions :)