My friend is delusional and planning to run away to Korea to meet a pop star

We are a trio me( my nicknames are chutiya or ae bsdk sun ), nigga and kamini patel. Few months back nigga came out as lesbian and opened up about her deep love for a Japanese based female kpop star named Sana . She is not joking she is so serious about her she even wrote three essays expressing her love for her and a separate short paragraph on what corny things they will do if they will get to meet eachother in her diary which she showed me . She has kept photos of Sana in between her academic books . Nigga is 18y/o teen in 12th standard and Sana is 28 y/o kpop star. Few days back she said she will date only Sana and she will go to Korea to meet her , she even made flowchart on how she can meet her . I have explained her so many times by giving logical reasons that why there relationship is not possible and she is just being delusional .

Guys pls tell me that what should I say her next time if she brings up this topic , it should be something offensive and logical.