Complex sentence: Bremer's inappropriate behavior also showed itself at a Blood, Sweat & Tears concert on 23 December 1971 when he kissed a woman not in his group while waiting to get into the concert.
Split into simpler sentences: Bremer's inappropriate behavior also showed itself at a Blood, Sweat & Tears concert in December 1971. He kissed a woman not in his group while waiting to get into the concert.