I guess it's the fact that it was teenage girls and ONLY teenage girls (if that was the case).
The actual actions taken (the massage as described) seem to be no different than how my wife (this was her comment) and I are "abused" at least weekly by our massage therapists, both of whom are of the opposite sex as us (our choice). One difference though is we are not only topless for the massage. We of course, are consenting adults and I think none of us (incl the therapists) find it "titillating". It's relaxing and therapeutic for us, but i think it damn hard work for the therapists. (And Robert Kraft would not be interested in the place.)