16/05/25 Edit - Cleaned up and attempted to simplify the ideas.
More Suggestions:
The following would make sense for the stocks but could also happen else where.
General NPC interactions:
Player characters can be force fed items with resistance significantly harder if mouth is currently forced open as an additional use of consumables (example: pain killers) already present.
Another possible interaction if the PC's ass is exposed is getting spanked - seen the option after beating one of the other NPC's so extending that interaction to the PC would make sense, if not already the case.
Lactation NPC interactions:
With lactation enabled, the option to attempt to be milked by them could also be a possibility along with a lactation related reputation increased from being milked.
Options to do so could include use of a portable machine, hands or the mouth with the major difference being flavor text along with the option to spit or swallow if the mouth is used.
Watersports NPC interactions:
With watersports enabled, the player character and NPCs could have the additional option to urinate on another character to gain 'alpha' reputation with the one urinated on loosing 'alpha' reputation and in both cases could wash away semen from the area and/or could cause an alternate debuff.
---Keep up the good work developer but remember to rest when you need to .