I was with my ex the first time I tasted a peanut butter pie crust sundae. At that time he was not my ex, of course—he was my very new boyfriend. I was the perfect age to shout-sing Taylor Swift (when you’re fifteen and somebody tells you they love you, you’re gonna believe them) and mold my identity around everyone I liked, pushing against their boundaries in lieu of forming any of my own.It was a delicious sundae. I’d been to my hometown’s local ice cream chain many times before—I still carry golden memories of using the uneven exterior beneath the walk-up window as a little kid rock climbing wall—but I’d never ordered anything except vanilla soft serve with krunch kote. The peanut butter pie crust was a revelation.It was his revelation.My ex knew about this delicious thing—hot fudge, peanut butter, graham cracker crumble perfection—first, and he shared it with me, and I felt that bonded us more deeply. Even when I ordered our favorite sundae without him present on the increasingly rare occasions I hung out with my high school best friend or sister, I thought about Matt. Peanut butter pie crusts were ours. Everything we did together, even just a single time, was ours. My world existed in shades of him.But then I left.I mean, it wasn’t that simple, my departure. Those months, after so many years, were a snotty-teared mess. But finally I came out of “us” as “just me”, and even though we weren’t yet married (I had to cancel the DJ and photographer, deposits lost) I found myself internally battling for custody.We didn’t have property or pets or children. But we had our own version of a life, the kind college students can easily build: favorite restaurants and TV shows and memories. Prom photographs. Mutual friends. Peanut butter pie crust sundaes. We were too young when we started dating. (I was too young.) I’d yet to build my own sense of self, and he was too willing to act as my backstop, and so I became his shadow, his shape, his image—“Matt’s girlfriend”, not “Haley as a person”.What was ours and what was his and what was mine?I wish I could tell you I ordered the damn sundaes and stopped thinking about him. That I still played “On My Way” by Phil Collins just because I liked it. That I said “these preferences are pretty tiny and trivial, anyway, and they don’t have to have anything to do with him”. In reality? My stamina improved, and I jogged faster over time, but the memories stayed on my heels.When I started dating Sean, we went to our my beloved ice cream chain before I was ready. “We passed a soft serve place that sells one pound cones!” my new boyfriend announced when I arrived to stay with him and a few other friends at an up-north cabin. “We have to go!”“I grew up in Wausau! Of course I know Briq’s,” I said. It still makes me think of Matt, I didn’t.I told Sean to order the pea