This is a real problem: everything you describe is perfectly legal, everyone involved thinks its okay, honorable, decent and right, and any action by you to interfere in their lives makes you look like a crazy person butting into things you have no right to mess with. Worse, you are just a neighbor with no connection to any of it at all. That's a toughie.

You could try picketing with a sign? Walking up and down in front of the young woman's house, chanting or yelling? You'd need a good, catchy slogan, though. That can be tough - making up a good slogan to yell isn't easy. I mean, you can't just yell "I'm really bothered by what all of you are doing with your lives and everything you think is acceptable!" - it's too long and it isn't catchy. It's to the point and accurate, but it lacks 'zing'.

At the very least, you could show up at the wedding, if it comes, and be the person who objects and interrupts it all. You could air your grievances that way, and maybe that would wake everyone up. I mean, they actually ask if anyone objects, right? That's a legitimate 'in' you could use.

It's really difficult being the only person who has a correct point of view when all the other people involved have no connection to you and are absolutely convinced they are right. Maybe you could look for ways to sabotage the relationship that everyone has agreed to allow to exist? Maybe dig up dirt on the cop, or even the young woman so that he no longer wants her. You could work to make both of them look so bad they break up.

Or, you could try to wreck the family that is allowing this and who thinks its entirely proper. A little digging through records can surely find out something incriminating - and the guy is a cop, after all. With enough effort you could save that young woman by destroying everything that supports all of this: her family, relatives, friends, other neighbors that are not you, the cop, his family, his friends and neighbors and, if necessary, the majority of the town you live in.

I mean, if you feel strongly enough about this, and clearly you do because your one bad experience makes it clear that every other possible experience that is even vaguely similar must, logically, also be just as bad. That's only reasonable, and I support you in that. Logic is logical, after all.

Some people just need you to live their lives for them, because it is clear that they don't know good from bad like you do. Thank god for such self-sacrificing people like you. You are truly a saint.