Hmm, … Bruce Willis' dubbed German voice is actually pretty similiar to his real voice.

It's a little wird, and I don't know if I can properly explain it, but actually it would be "Das ist kein Boobie!" Though the german version of "Boobie" is a feminine noun, you'd still use "kein" (the male/neuter version) instead of "keine", because "Boobie" is foreign word.