It’s been two months since you broke up with your ex, but yet and still, you sleep in his hoodie.

Well according to one psychotherapist, there’s a reason why you let him go, but not his beloved piece of clothing.

Jenn Mann is the author of The Relationship FixShe compares our desire for a former lover’s clothing to that of a child’s security blanket.

“Boyfriend clothing is what we call a transitional object,”  Mann told InStyle. “It allows us to bridge the gap between us and another person.”

According to Mann, a sweatshirt is like an upgraded version of a Letterman jacket. During a relationship, something like a sweatshirt or T-shirt serves as a symbol of unity, ownership and togetherness–a special kind if intimacy.

But once an absence is made permanent, like a breakup, that item of clothing takes another function.

“We hold onto an object that smells like them, reminds us of them [which is comforting],” Mann said.

You can be dead set on breaking up, but that craving doesn’t just magically go away. Neither does the scent of an ex held in their clothing.

“Scent has a lot to do with how we fall in love. We are hardwired to favor the smells of men who have immune genes that differ from our own,” said Mann.

So does this mean you’re not over your ex? Not necessarily.

“I am very happily married, and I still have a box of photos and love notes from some old boyfriends going back to my high-school sweetheart, which my husband helped me organize when we moved because I’m a sentimental person,” says sexologist Jill McDevitt, Ph.D. “A shrine is a different story. But mementos, particularly of a relationship that occurred at a pivotal time of one’s life, does not necessarily mean you are not over them … [it] is a reminder that you had love in your life.”