U kinda bad tho

Exactly especially since he knows that his friend has strong feelings for her...I feel as though he has an inferiority complex against leo since they both are sons of dukes and their heirs to the
dukedom...maybe he has an inferiority complex I kind of see it coming i mean leo is the ml afterall and they are always made to be perfect maybe he just wants the woman leo can never have much more the woman that dumped leo....idk just my take on it ╮(￣▽￣)╭

Damnnnn he’d have to be real fucked up and petty to do that I’d automatically hate him

If you can get over your exes, why your friend can't have them? If they love each other, I feel like it's not right to destroy an union just because of yourself. At least if you got over him or her. It's pretty selfish.
Obviously, I understand that if you still like your ex, then yes, your friend shouldn't do that but if you don't like him anymore, I feel like it's selfish.

It can take years to truly get over someone, and even if you move on there can still be unresolved conflicts and infected wounds. Three months okay, no biggie you could ask if they're OK with it, or if they're just generally cool about the break-up, but after he has come to said friend, crying and being heartbroken? Ouf.

Besides, it's rare that someone falls in love at first sight like that, there's a process of getting to know each other where the friend choses to prioritize their superficial attraction over consideration for a friend. If I had a friend fell for a guy not knowing that's its my ex that's another thing. I wouldn't feel as hurt, because there was no point where they thought "It's worth potentially hurting my friend's feelings so I can fuck this person". Isn't that pretty selfish? Certainly shows how much you value that friendship.