In terms of being into weird random stuff probably from the very beginning. I remember reading about a study where they taught mice to associate the smell of lemons with sex, and they developed a strong preference for lemony partners. The takeaway was there 'is' no universal set of sexually relevant stimuli, it's learned. So if mice do it I'd bet homo erectus was getting up to some freaky stuff on occasion.
The other definition would be non-normative sex acts, which makes you wonder when did we start having norms for how we have sex. Like I don't imagine people were doing missionary with their clothes on in the back of the cave.
In terms of being into weird random stuff probably from the very beginning. I remember reading about a study where they taught mice to associate the smell of lemons with sex, and they developed a strong preference for lemony partners. The takeaway was there 'is' no universal set of sexually relevant stimuli, it's learned. So if mice do it I'd bet homo erectus was getting up to some freaky stuff on occasion.
The other definition would be non-normative sex acts, which makes you wonder when did we start having norms for how we have sex. Like I don't imagine people were doing missionary with their clothes on in the back of the cave.