Jesus was most like referring to the crowd themselves. The New Testament is filled with references to the church being "the bride" and Jesus being the "bridegroom." Nothing too shocking here, and since the sentence is incomplete, we'll never know.

It is more likely that he is calling the crowd his wife. The New Testament is flooded with symbolism of the church being the "bride" and Jesus being the "bridegroom." The in-completion of the statement leaves too much guess work. We will never know.