YOU SAID:

i lie to my boyfriend by sleeping with his bestfriend :/

INTO JAPANESE

私は彼の親友と一緒に寝ることによって私のボーイフレンドに嘘をつく:/

BACK INTO ENGLISH

I lie to my boyfriend by sleeping with his best friend:/

INTO JAPANESE

私は彼の親友と一緒に寝ることで彼氏に嘘をつきます：/

BACK INTO ENGLISH

I lie to my boyfriend by sleeping with his best friend:/