Advice

So I was friends with this girl at work. Well her ex boyfriend and I have been best friend for a pretty long time, even before they dated. I’ve seen him in his highest points in life and lowest since I’ve met him. They dated for a very short time (around 3 months) until she broke up with him. Well , after that he fell for another girl and she ended up just using him for his money. During then and after that we became even closer. Like talking every single day all day kinda best friends. Well he came out and told me that he liked me. And honestly, seeing the way he is and the way he cares so much made me fall in love. So we’ve fallen in love with each other. I mean, he’s as happy as I am with each other. I honestly think I’ve found my soulmate. But, my friend and I aren’t that close of friends anymore like we barely talk, but we still work together when she comes home from college and she’ll occasionally ask me who’s new at work and stuff. Am I that bad of a friend for falling in love with her ex boyfriend? I asked my bff about it and she said you don’t choose who your heart wants. And she feels like she was only with him just because. I don’t know I honestly don’t care what they think sometimes, but then sometimes I think, am i really that shitty of a friend for letting myself do that?