... so you can or cannot avoid nie wygłupiaj się? You're contradicting yourself now.
I cannot agree with you Majlo. Ive found synonimus to word 'silly', and I don't see any reason to translate the topic as "Nie wyglupiaj sie". As in
there is no one translation with silly.
I could say, "Nie badz niemadry' - for 'don't be silly, ' nie wariuj' for don't be crazy.
I cannot avoid 'nie wyglupiaj sie'.