Dallin's Predicament

So here is a little background:

Mindy-16 

Babysitter from Rexburg, ID

Ever since we moved to Rexburg, ID, Dallin has been in love with Mindy. He always said he was going to marry her. (For those of you who know Michael, you know what's really going to happen!!) When we moved to Utah, Dallin had a very hard time leaving her and wanted to call her all the time. A little while ago, he started to ask about her...A LOT!!

Hailey-5

Friend 

Hailey lives down the street and Jenn's (one of my girlfriends) daughter. When she and Dallin play together, there is never any fighting, crying, or getting mad. They play awesome with each other. A couple days ago, we were doing Dallin's birthday party invites and he was writing his friend's names on the envelope and putting the invites in and sealing them. After dropping them off, we had Hailey's to give her. I had it in my hand and felt that it was a little thicker. He had put a piece of gum in hers and only hers. My initial thought was, "Oh no....another crush." I asked him about it and he said, "Cos I like Hailey!"

Where the predicament occurs: 

A couple days ago, I was helping Jenn pack for a cruise she and her hubby are going on for a couple weeks. Dallin and Kailee came with me to play/entertain Hailey and Weston (hailey's lil bro). Jenn and I were talking and in comes Hailey looking very sad. She looked at me and said with a serious face, "I need to talk to you" and she led me into her mom's room. The girl had my full attention. She said,"Dallin has another girlfriend. He told me her name is Mindy" in her saddest voice. I knelt down to look her in the eyes and she finished by saying,"He just broke up with me!!" As she THREW herself on her mom's bed covering her face. I had no idea what to do except what I normally tell my kids when there is a problem. I called Dallin upstairs and told him that they needed to work it out. It was all I could do to keep a straight face. I then told Jenn and we both lost it. What are we to do?