Wiktionary
ride bareback
vb. 1 To ride a horse bareback (that is, without a saddle). 2 (context slang English) To have anal sex without using a condom.
Usage examples of "ride bareback".
Are you going to give me your promise you won't ride bareback again?
If she admitted that she liked to ride bareback, as some warriors did, he would naturally conclude she wasn't much of a lady.
But then the English cut down the trees, and so now it is our custom to ride bareback.
As well his mount had been saddled, Sharra thought, just as someone threw a fur-lined wrap over her shoulders, for Groghe was no longer agile enough to ride bareback like his sons.
But then the beast settled again, and he got his seat, thankful he'd learned to ride bareback.