Don't be that guy. Sack up and tell her how you feel now. Because there's a difference between private embarrassment and a public beating. I am not a violent man, but if a guy stood up at my wedding and went The Graduate, he would leave needing to be helped out. Or, you can realize that your friend is happy the way she has it and accept it and be happy for her and just leave it alone. Sorry to say, but life ain't a fairy tale bro. Either you take what's yours or sit down. In summary you have two options: Cowboy the -blam!- up Or Sit the -blam!- down

Do it. If she is the love of your life show her it. Be sincere and and keep your voice solid and straight. Display your love for her.

At the end of the day you can only do what you think is right and the chips will fall as they may.