I don't remember the exact phrasing, but it was something like "he has a predilection for biting children [implied: out of all age groups]", but you're not the only one who came away with the pedophile rapist insinuation, and it's kinda hard to tell with JKR just what she meant and what she didn't because she evades those sorts of answers because of the children/parents who might hear/read her interviews.

For example, the spells that Aberforth Dumbledore used on goats; it was insinuated that it was to, er, fuck them, but she said something about making their horns curly or something silly like that when asked in front of children.

Also, Umbridge and the centaurs. O__O I don't remember if that was ever asked in an interview, but no way is she going to admit whether or not there were rape undertones there.