People no more need to be unfaithful just because they have the privacy that would make an attempt possible than they will be faithful, loving and respectful just because they are rarely out of each other's view.
Here's my personal take on it. If your significant other is going to cheat on you, there isn't a damn thing you can do about it. So you have a couple of choices. You can punish your significant other for a "crime" that they haven't committed, so long as you understand that sometimes people get tired of being punished for something they didn't do. And often times when they are tired of it, they decide that if they are going to live in a perpetual state of being thought guilty of something they haven't done, why not do it? So it's possible that you can "drive" you significant other to cheat on you when they probably wouldn't have otherwise.
Or, you can choose to trust, knowing that it's still possible to get hurt. But when you trust someone, often times they repay your trust in them tenfold with more respect than you knew was possible. They recognize you for the wonderful person that you are because you allow them to explore their potential without constantly trying to keep them in their place.
When you choose not to trust, there is nothing that your significant other can do to make you trust them. You can keep that person chained inside your home, and you still won't trust them. Your inability to trust isn't someone else's fault, it's your own personal inadequacy. It's fine not to trust someone who has given every indication that they aren't trustworthy. But you should understand the difference between someone proving themselves untrustworthy, and you having unreasonable expectations of how another personal should behave.
Respect is a two-way street. You can overpower and force someone to be respectful to you because they fear you. But you can't force someone to respect you unless you respect them.