Oh, sure, there are a few couples, like Beth and John, who are an automatic assumption when it comes to dating and events like Homecoming, etc., but by and large, there aren't a lot of couples in Matt's group of friends.
Ali and Matt have been friends for years and years. They swim together with CSC, they grew up through the years in ICC/IYC choir, have done countless swim meets, sang in countless musical performances, traveled in Italy together with the choir, etc., and there is just a certain amount of closeness that develops from those shared interests and times together.
They are like an old married couple together. One looks out for the other, each having their own ways of just motoring about together. So it was that Matt took Ali to Homecoming...literally: he picked her up, took her to the party, took her to the dance, took her to Stephanie's party afterward, and then took her home. But it wasn't a date. They weren't going to Homecoming together. It was just Ali and Matt motoring about in their usual style.
A nicer friend Matt could not find. Are they dating? Absolutely not. Are they secretly hoping to date? Absolutely not. They are The Couple That Isn't. They are just Matt and Ali. And they had a great time at Homecoming!
Trying to get a photo of the two at Margaret's party...both on their cell phones chatting away with others, Ali trying to get her mom to hurry up and get to the party to take photos, etc., and Matt trying to talk Taylor into coming along to the party and having a good time. Taylor had plans with girlfriends, but Laurie I did get to see.