I picture it being both. From what I've read so far, Frank and Matt are extremely violent towards each other, but where Matt always tries to fight fairly, Frank will cheat to win. It takes on an abusive note because Matt believes Frank is redeemable, and Frank will sometimes use that to manipulate him. Frank's also very good at taking advantage of Matt's moral insecurities and shaky mental health.

I can actually see Matt allowing himself to be trapped in the relationship, hoping that by staying with Frank he'd be able to save and redeem him. If anyone's going to help him get out of it, I picture one (or more) of the other heroes: maybe Jessica, Luke and Danny realize what's going on, or Spider-Man sees it and turns to them for help, or maybe Captain America picks up on it when he's forced to work with the two of them (Cap considers Matt a friend in the comics but he despises Frank- so finding out Frank's abusing Matt would lead to an epic beat-down).