Muslims what do you think of.....?

I've been reading the Qur'an since I've been interested about Islam. I learned that men may take as many as four wives as long as he can treat them equally. I asked my boyfriend about this since he's Muslim and him and his father both said that the statement men can have as many as four wives as long as he can treat them equally means that Islam is against multiple wives. Since it's impossible to do justice and treat them equally you may marry only one women. So my question is what do you think of the men who actually take more than one wife and do not abide by God's rules?