Way before I ever heard of MBTI, I remember telling someone, "I want to be able to say what I think and still have everyone love me anyway." I think that is classic ENTP.
When I blurt out something like "Bananas are disgusting." I 99% believe it and assume I must be right. However, I am very open to the idea that there's a possibility I'm not. My comment is an unconscious invitation to you to tell me something new and fascinating that I didn't know about bananas that will interest me or change my mind, like "Bananas actually caused the French Revolution," with back up facts, of course.
As I got older, I realized that this is a unique communication style and not universally loved. So I now try to be more aware of the group I'm with and think before I blurt out something. Still, sometimes I forget and blurt out "Bananas are disgusting." People who know me well know I'm really saying "Right now, bananas are disgusting to me."
Even now, I would easily engage in a spirited debate about bananas with you because to me it would be a fun, intellectual tennis match. But, here's the thing. Any ENTP believes that he will win any debate, ruthlessly, if necessary. A good way to end off the debate would be "You have not convinced me, but I will think about what you have said." That response is respectful to give and receive.
You can always learn more about ENTP strengths and put your focus there, looking for ways to bring out the best in your ENTP. Some martial arts teach practioners to use the attacker's own strength against him. I am not saying to use their strengths to thwart them, but to move the relationship away from being irritating to you. If a colleague came up to me and said, "Hey you're good at this and I need help with it." I would be inordinately pleased -- and actually respect them more for realizing it.
Often ENTPs have a vision; what is his vision? Can you help him see how he can utilize your strengths to help him achieve that vision.
These options are more work for you, but will guide the ENTP toward maturity and balance.
Bottom line: hit them with a hug