No, I'm actually not. I know marriages have rise and fall. But even in the fall, I expect my eventual husband not to ever turn to another woman for anything, unless it's his mother. I know this probably gets harder to keep up with time, but it's still a choice on my hypothetical spouses part to avoid any kind of emotional closeness to another woman. I know some women are sharks sniffing out blood, but men aren't helpless creatures unable to avoid advances, and while they may not always make the right choice, I EXPECT them to.
Again, who knows, maybe i'm naive, but I'd rather get blindsided than accept that it's going to happen. That's a sustained misery I couldn't live with, personally.