Lock up

I walked out of the English building after class. Bright. I thankfully took my sweatshirt off before I left class. I unlocked my bike.

"You gotta get yourself one of these," a man said.

"What?" I stopped, glanced up.

"See how mine is clipped to the bike?" he pointed to his bike lock, the same model as mine but attached to his bike.

"Oh, yeah. Okay." I felt uneasy as the White Sox hatted man stared.

"Yeah. I'm in, and now I'm out. You're still unlooping yours." He hopped on his thick tired bike and rolled away, cackling.

I wrapped up my lock and put it in my bag. I rode to work. Is unlooping a word? I didn't know the answer.