Can I start dating my friends ex two weeks after they broke up?
It depends but why would you date your friend's ex, wouldn't that bother your friend?
I don't care, I like to act like a vulture.
It is rude and unsympathetic to immediately start to date someone your friend just broke up with. It shows a lack of consideration for your friend's feelings. You should look for other people to date that are not exes of your friends.
How is this a bad thing? If he's going to be upset, he should have never slept with her in the first place.
It's like a bro code that you don't date your friend's ex because it will put a dent in the friendship. It's risky, but I suggest you talk to your friend first so it doesn't become a surprise. It will be hard for him to accept it, but maybe he is understanding about it.