Personally, Im guessing that the Reverend had some unresolved issues in his past and was using the time that his wife was away to "play" and act out what must have been a traumatic experience of his youth.
Sheesh.
Or simply enjoying what would have fine if he didn't have the Fundie hangups and could have participated in an open and accept way with safety considerations included.
The only tragedy here is that his religious hangups pushed him towards secrecy and that resulted in his death.
Aslan is not a
Tame Lion