YOU SAID:
the man child was acting chilish yet manly
INTO JAPANESE
男子は子供っぽくて男らしい演技をしていた
BACK INTO ENGLISH
The boy was acting childish and masculine
INTO JAPANESE
その少年は子供っぽくて男性的な演技をしていた
BACK INTO ENGLISH
The boy was acting childish and masculine
That didn't even make that much sense in English.