My best friend just got engaged and I hate her fiancee.
What is your reason for hating her fiancee anyway?
I just feel like the man she is marrying is way to controlling of her.
I understand that you don't like controlling people, but supporting friends in their engagement is the right thing to do. Set aside your judgments and be there for your best friend.
I don't want to control them by asking them where they are going or what they are doing. I just want to see and be able to spend time with them. If they want to go out and bond alone, it's OK.
I agree that you should be able to spend time with your friend. But it's fairly common for people to spend less time with friends when they're in a relationship. It's likely your friend is genuinely happy with this man, hence why she is marrying him.