YOU SAID:

crashing into someones party

INTO JAPANESE

誰かのパーティーに衝突する

BACK INTO ENGLISH

crash into someone's party

INTO JAPANESE

（人）のパーティーに衝突する

BACK INTO ENGLISH

clash with someone's party

INTO JAPANESE

（人）のパーティーと衝突する

BACK INTO ENGLISH

clash with someone's party