The clown/child predator story I was describing in class ...

... is "Holiday" by M. Rickert (2007), the title story of her upcoming collection from Golden Gryphon Press. In the meantime, it can be found in two 2008 volumes, The Year's Best Fantasy and Horror 2008: Twenty-First Annual Collection, edited by Ellen Datlow, Kelly Link and Gavin J. Grant, and The Best Science Fiction and Fantasy of the Year Volume 2, edited by Jonathan Strahan.