Secretly filming and distributing a ‘girl’ performing a sex act.
I'd like to highlight the filmer's misogyny in thinking it's OK to film someone who he perceived to be female and put the footage online.
It also strikes me as a very one-sided encounter. Obviously, the fellator had his reasons for keeping it that way, but a decent man would want to reciprocate. This again is an aspect of misogyny: that it's ok for women to give men head and get nothing back.
ETA: the fellator might have two reasons: not wanting his victim to see or feel his genitals being the obvious one, and a desire to live up to his misogynist idea that women exist to service men à la Andrea Long Chu's "open mouth expectant asshole, and dead dead eyes".