I despise the man my friend is marrying

My best friend is engaged to a guy I absolutely despise. I know he wants her only because of her looks and the money she earns. He knows I don’t like him and he always pretends to be very kind to me when she is around because he knows she can’t stand the idea of someone disrespecting me. I can’t say anything about him to her because I have no proof of his intentions, but I am afraid because I have a feeling this marriage will end the minute he gets what he wants from her. She is my closest friend and I worry about her, so I feel helpless because I don’t want to stand around and do nothing. Should I say something?
If this is your closest friend and you have something on your mind, you should say it even if you have no way of backing it. If she trusts you, and values your opinion, she will listen to what you have to say and not dismiss it outright. These are adults, who will probably make a mistake or make it work. It’s impossible for anyone outside that relationship to be sure of how it will evolve or end. You have to make sure you are there to support her in any way you can, and that she is aware of this. There is not much else you can do beyond that, because life has lessons for each of us and we alone can learn them, even if it is sometimes the hard way.

How can I try and convince my girlfriend to dress more appropriately when we go out in public? She wears skimpy clothing, which bothers me.
How do you have any right or control over what she chooses to wear, given that it is her body and her clothes? If she feels comfortable, shouldn’t you be happy about that? You are her boyfriend, not the custodian of her body. If she doesn’t police you, why do it to her?