If you read the account, there are explanations throughout that describe what their relationship is like. In several places, it describes that they fought all of the time over material goods, and that they fought so loudly that people could hear them. Tom often walked away from these fights with signs of physical abuse from his wife. Tom also refuses to strike a bargain with the Devil at first, simply because his wife wants him to; that speaks of hatred and spite. Then, when she disappears and he finds signs that the Devil has killed her, Tom actually feels grateful and relieved.
All of these things tell us all we need to know; their relationship doesn't sound very pretty, does it? I hope that helps!