Two versions of the interaction with the centurion have been posted. One refers to the ill one as his servant and the other refers to the ill one as his son. The billboard does not claim that Jesus was gay, so it must mean that the centurion and the ill person were a gay couple. So the billboard is saying that the centurion was having homosexual relations with his son (i.e. he is a child molester) or with his slave (probably non-consensual). Neither makes gay couples look real good. They probably need to rethink their PR on this one.
Master and Servant is a traditional set of roles in homosexual society. Maybe this is why they pick up on it.
They also saw the Passion as an S&M flesh feast for the eyes.
They are sick. Mentally sick.
The idiot who put up the original billboard is ignorant of history. Homosexuality was actually quite taboo in the the Roman Republic and early empire period, and it was "officially" frowned upon in the legions (though some activity doubtless occurred).
Some Romans who were of the homo persuasion perversion would spend a lot of time on "business" in Athens so they could find all the bum-boys they wanted.
It’s all prohibited by Scripture.