*GASPS* ROYALTIES!!!! Lol... Just kidding. Sure, use it. But I would ask, that I get a free copy of the story, and if you try and sell it for any monetary reward or currency or other product/service, I get a share of the money, assuming it is on a reasonably large scale. I need to hire my lawyer to word this better...
In all seriousness, I'm not hugely bothered if you use it, but a little something is always nice.
No obligation.