Female lead fake dates male lead to make other guy jealous

Probably not really what you're looking for, because it's more a matter of moments than a whole elaborate fake-dating scheme, but both the leads in Suspicious Partner help each other out by pretending to be in a relationship with each other to make their exes jealous / to make them look less pathetic in front of their exes. 

 AH:

Probably not really what you're looking for, because it's more a matter of moments than a whole elaborate fake-dating scheme, but both the leads in Suspicious Partner help each other out by pretending to be in a relationship with each other to make their exes jealous / to make them look less pathetic in front of their exes. 

 Amaury1514:

Sorta similar but completely opposite. She “dates” the second lead to make the male lead jealous 

- hi my sweetheart 

I've seen both of these, but thanks.

you might have already seen it, Marriage not Dating. She gets into a contract relationship with male lead to make her ex jealous. She ends up being a fake fiancé, her ex is close friend of male lead.