Usually, when someone offers a “Buy X, Get Y Free” deal, Y is something that costs the same or less than X. But that is apparently not the case for a deal currently being offered by Victoria’s Secret.

Consumerist reader Kenny was confounded by the math behind the offer: buy a sports bra and get a free “sport pant” to go with it.

Makes sense for VS to be pushing workout gear, with so many New Year’s resolutions waiting to be fulfilled, but it struck Kenny as odd that lingerie-loving Vicky would give away sport pants that can go for as much as $72 just because someone bought a sports bra, which can cost as little as $30.

Here’s the deal:

The promotion, which runs until 11:59 p.m. (EST) on Jan. 10, has several caveats, including one free pair of pants per customer, and the purchase can’t include a clearance item. Additionally, to actually redeem the deal, shoppers must enter a code during checkout.

Of course it’s possible the retailer is offering the deal as a way to move inventory, or in the hopes that once shoppers have one pair of pants in their bag they won’t be able to resist adding another pair. Or the company could be hoping that people forget to enter the code for their free pants, if they have a cart full of items.

We reached out to VS to ask these very questions, but have yet to hear back.

It looks like some VS shoppers have already caught on to the unusual offer, since a number of items have already sold out.