Have designs on somebody
Definition 1 of 1
Pro Tip 1/3Secret Intentions
The phrase often implies secret or dishonest intentions toward someone else's belongings or roles. 
He's always complimenting the boss; I think he has designs on her position.
Pro Tip 2/3Negative Connotation
Using this phrase suggests that someone's intentions are not only secret but possibly harmful or unfair. 
She has designs on her friend's inheritance, which doesn't seem right.
Pro Tip 3/3Cautious Use
Be careful when using this phrase, as it could offend someone if misinterpreted or if the accusation isn't true. 
I wouldn't say he has designs on my project; he just offered to help.