Last weekend, I got to be a bridesmaid in my best friend's wedding, and I loved every minute of it.

I was so excited to be included, all summer I had to stop myself from calling it "our wedding." I loved seeing her try on gowns, I loved the bachelorette party, I loved the bridal shower.

I even loved my bridesmaid dress.

I'm a really good friend.

I did everything except diet with her.

I'm not that good a friend.

The wedding weekend itself was full of spectacular events, ramping up in order of magnificence. And when the big day arrived, it was more beautiful than anything I could've imagined.

And I didn't mess up! I gave a heartfelt, if inebriated, speech at the rehearsal dinner. I did not trip and fall when we processed down the aisle.

I did accidentally sit on her veil when we were getting ready, but nobody saw.

All told, she got hitched without a hitch.

At the reception, I gave the bride space to spend time with her guests and enjoy the few breathers alone with her groom. With the pre-wedding events, especially the epic bridal party primping-session that had begun at 10 a.m., I'd gotten a lot of girl-time with her.

So I scanned the dance floor looking for other friends to boogie with, and I spotted my best guy-friend from childhood.

We've always had each other's backs on the dance floor, whether I was making sure he had someone to slow-dance with in seventh grade, or when he rescued me from going to the senior prom alone after my boyfriend dumped me a week before.

He's not a friend, he's a brother.

As we broke it down to Beyoncé, same as we had back when she was in Destiny's Child, it struck me how surreal it was that we found ourselves together that night.

In a twist of fate, he was invited because his fiancée is the bride's best friend from childhood, and we introduced them.

Not only that, this very wedding might not have happened if we hadn't introduced them, because his fiancée was returning the matchmaking favor when she introduced the bride to the groom!

We're better than Tinder.

I shouted to him over the music, "Do you realize we've been friends 18 years?"

"Since sixth grade, baby!"

"And in three weeks, we'll be dancing at your wedding!"

"I know, it's crazy."

But maybe it isn't that crazy. Maybe this is how it's supposed to work.

One good heart tossed into the world ripples out to embrace other good-hearted people.

Love multiplies.

And each outer ring protects the inner ones.

I didn't see that before. Amid all my excitement about my best friend's wedding, I had a little apprehension, too. Not that I'd lose her - we studied abroad in college together, which ensures lifelong friendship, by blackmail at the very least - but apprehension that things might change.

Come to think of it, I had the same apprehension when my guy-friend and I graduated high school and left for college 600 miles apart.

And yet, here we are, friends old and new, tighter than ever.

Change can be a good thing, despite the bad press it gets, and even close friendships have room to grow outward. It'd be too hard for one person to gather enough people to love all on their own. It's a group effort. And the whole is greater than the sum of its parts.

At the end of the night, all the guests lined up on either side of the long entrance hall for the grand send-off of the bride and groom. We cheered and snapped pictures and shook tambourines as the newlyweds scampered down the aisle, laughing and waving on their way to their getaway car.

I blew them a kiss that I'm not sure they saw. But that twinge of melancholy at seeing my best friend wave goodbye and disappear into the limo lasted only a moment.

Yes, she's about to embark on a new phase of her life. And, yes, my role in her life may change. But as time goes on and our hearts grow more rings, we don't have to leave anyone behind. We can hold on to each other, and collect new hearts to hold, from this day forward, as long as we all shall live.

Look for Lisa and Francesca's new humor collection, "Does This Beach Make Me Look Fat?" in stores now. Also, look for Lisa's most recent novel, "Every 15 Minutes," in stores.