Actually, I see this (the development of Debbie in general) as one of the most difficult questions Altos and Herdone have going forward. Bisexuality is an option, yes, but there will be a narrow line between overusing clichés and becoming unbelievable or giving up the feel of the game.
Of course all of this will be a non issue if Debbie's interactions with the MC are completed as they are now, but if they were to intensify, A&H need to make sure it isn't all forced against her will and amount to rape (which would be possible in some other games maybe, but not in this). At the same time the "magic dick contact cures lesbians" of course is utterly nonsensical. Yes, there is a line, using respect for the headmaster as a person and thephysical pleasure possible, but it has to be walked carefully.