Deuteronomy 22:5 states definitively that a man should not wear women's clothing. Beyond that, we must use biblical principles to guide us. For example, modesty ought to be a hallmark of every Christian's life. We can therefore conclude that men, along with women, should dress modestly (1 Corinthians 12:23; 1 Timothy 2:9). Since the Bible describes revealing the thigh as nakedness, modest clothing would include pants that are long enough so as not to reveal the thigh (Exodus 28:42).
Much of the Bible's instruction is implicit rather than explicit. In other words, it is there only for those who have eyes to see it. If a man wants to wear clothing that immodestly exposes his body rather than clothing that covers it, he can easily justify it from the lack of explicit commandments. But for those who desire above all else to please God and present a godly appearance before the people of the world, they will see clearly the heart of the Word rather than the mere letter.