Please help?! I'm really starting to fall for my best friends ex..?

ugh. so lemme tell you the whole story, it might be alittle long. my best friend dated this guy for 9 months, they looked wonderful together. my best friend broke up with him a month ago, she says she just didn't love him, and didn't feel happy anymore. he loves her, ALOT. he would always come to me (because i'm her friend) and tell me everything, ask me questions, just talk about her. We'd literally stay up till 3 on the phone, almost every night a week for 2 weeks. we eventually would talk about our lives, and i'd talk about stuff i was going through, and he'd do the same. we are SO alike, and can literally talk about anything. I love his sense of humor, and the way he looks at things. I know it's so dumb of me to have these feelings, but for some reason i keep encouraging them. he'll text me out of random now, just to talk, we've become decent friends. i won't admit to these feelings to him though because i don't want to mess up the friendship that i tried really hard to get. The problem is, he's still in love with her. and even if he gave me the chance, i know everytime he'd look at me, he'd see her face. and i don't want to put myself through loving someone who wants someone else. Plus, my friend is drop dead gorgeous, and i'm pretty too, but not like her. it's kinda intimidating. my friend says she's completely over him, and is already seeing other guys. i haven't told either of them about how i'm feeling though. what would you do if you were me? i'm so confused, i just feel like i'm holding onto a fairytale.