history: Our son is in the Army and stationed in another state. He will be coming to visit us next month on his leave. Our son in the Army is taking a leave to visit us next month.
current: Oh, you must be so excited! I have a son in the Army as well and I love when he gets to visit! 
next: Wow! So you can totally understand how I feel. You must be proud of your son as I am of mine.