For the past year, hundreds of sorority girls from the University of Iowa have attended a self-defense course taught by a man claiming to be an accredited instructor. As it turns out, however, he was a fraud—with a surprisingly ambiguous agenda.

Naturally, one would suspect that a heavyset, bald man who infiltrates a sorority house with a fictitious name is probably aiming to inappropriately fondle unsuspecting coeds. But, according to Delta Gamma member Rachel Kodner, there was “no ‘blatant inappropriate touching’ during the presentations.”

This, then, begs the question: What was the man, who went by the names David Portnoy and David Parker, really up to?

Apparently, selling pepper spray.

The Daily Iowan reports:

The presentations were offered for free, but the man urged the members to purchase containers of pepper spray he brought to sell. He set up deals, selling one bottle for $18, or three for $30, said Treacy Weldon, the president of Kappa Kappa Gamma. Almost everyone in the house bought at least one bottle, she said. The same was true in the Pi Beta Phi house and the Delta Gamma house, members said. Weldon said the man contacted her to pitch his services.

Devious, sneaky and 110 percent ingenious.

Still, anyone hoping to sneak into a sorority house in the near-future should probably avoid using the “self-defense instructor” trick, because it has officially been done.