[jmcclain]

You'll never be the bad guy if you're honest. So be honest with what ever you do. I would approach the ex first with the question of would it bother you if I date your friend. If she answers no, then still move slowly, but move ahead. If you're a good guy, which it seems you are since you are asking about a situation like this instead of just saying the hell with it, the ex will have no problem with you persuing a friend, if there's no fellings there. If there are, then the next discussion must occur about what to do with those feelings. Make her realize nothing's going to come of them, or move on to persue that relationship. If she's that good of friend to you, she's gonna see you date other girls and is going to have to accept that as a part of your life if she still wants to be a part of it too.

At the end of the day, be true to yourself and honest with those involved and you will be able to sleep at night no matter what comes of it.