He wasn't trying to be perverted, though. It was purely accidental, since she is taller than him & given that he was jumping from behind to surprise her with his eyes shut, this is where we--the viewers--come in, at this most awkward time. Still, it is a violation of her highly private personal space & yet, seeing as how she & he have been source comic continuity couple canon these past eight years (2003-2011)...well...you get the idea.
I can totally see Beast Boy doing that to Raven.. ON ACCIDENT..Of Course.. It makes me feel all giddy inside knowing that Beast Boy will get hurt because then Robin will make Raven heal him!!!!! Yay!!!!!!!! xD