Sticky situation😩

My guy friend is getting married soon. However, I just found out he cheated on his girl like 4 times with another girl. I do not know his fiancĆ© and we’ve only met once BUT I feel like since I know about this cheating incident I feel as a women I should tell her😬 should I tell this girl her fiancĆ© cheated or mind my own business and not get involved in this???