I feel like dating my friends ex.
Why do you want to date your friend's ex knowing there is bad blood there?
Because their relationship is over and I think it's okay to date them now.
It's understandable to be attracted to you friend's ex, but you might want to consider how dating them will affect your relationship with your friend. Your friend will probably be upset with you and it may be the end of your friendship with them. Please, at least talk to your friend before entering into the relationship with their ex.
I gotta do what I gotta do.
If they still feel hurt over the relationship you should talk with them about it. They might be really offended and not wan to be friends any more if you hide it as a secret.