To tell or not to tell?

A few years ago, I used to hang out with this girl all the time. She had a boyfriend and we all became friends and hung out together on a regular basis..one night, we were at her house and her boyfriend sent me this text message that was kind of ...well...

inappropriate for a guy who has a girlfriend to send to another girl.
They had been having problems in their relationship at the time. He started to call me, and I told him that she was my friend and I couldn't ever be with him or hook up with him even if they broke up and were not together for a long time..I just felt like it was wrong.
After that he said..he agreed and he couldn't do it either but that there relationship problems had confused him into thinking he had feelings for me.
He begged me not to say anything...and I didn't because I promised..but I kind of stopped hanging out with them as much..and now she moved about an hour away and I haven't really seen her in a while at all...

The last time we talked she told me that her and that guy were engaged...
My question is...is it wrong for me to not tell her about what her boyfriend tried to do. It has been 2 years and I probably should have said something then, but I figured he was just confused and they would probably break up eventually anyway.
I just feel bad now because they are getting married..and if I were going to marry someone who once hit on my friend id kind of want to know...

I dont know if I should just leave it alone ( which is my instinct) since it was so long ago and nothing happened...or if I should tell her...

 
I'd leave it alone. Nothing happened and it did occur during a crisis between them. Saying anything now would do no one any good.

NO you should not tell her. I hate snitches, everybody do. But you did promise him especially. AND its uncessecary because they are happy now and he explained to you in the past that he was just confused! And who knows, maybe he even did that to get HER jealous you know? He probably do love her a lot. So let them be.

look im not one to tell you what to do see its all in the past maybe he was confused whatever if he continues the same pattern approach him it seems hes ready to be with her you choose what you feel is the right thing just before realize how happy they are and think of all the consequences ok