Remember that girl crush in college? The one that made you think you might be a lesbian? But then again you love your boyfriend, so maybe not? Well, stop right there. Science says it’s not that black and white! According to new research from the University of Utah, women’s sexuality can be shades of gray. Psychologists followed a group of self-described “lesbian” women for the past 15 years—having them label themselves as lesbian, bisexual, heterosexual or unlabeled over time—and amazingly enough, the labels flip-flopped along the way. The older they got, the more likely there were to check “unlabeled” too, another sign that sexuality might not fit into tidy little checkboxes.

MORE: Women’s Sexuality is a Spectrum