We are not Catholic and I while I would not make light of a sincere Catholic's beliefs, I simply do not believe that and do not accept it.
No offense, but if marriage isn't permanent then it isn't really marriage at all by any Christian definition. It's just a civil arrangement that is actually much weaker than a contract to buy a car. If you need any evidence of that, just see how many marriages end in divorce compared to how many people get out of contracts to buy a car after they've already taken possession of it.