5. “It’s not working because you’re too nice.”
Telling him that he’s too nice is confusing because he won’t know if you’re criticizing him or praising him. In the end, you have communicated nothing. Don’t mince words. For example, saying, “I don’t like you because you’re not manly enough,” may be cruel, and it may be like a dagger to his heart, but at least you’ve made yourself clear, which may help him accept your decision.