I mean he lets his soldiers gangbang you while he watches before joining himself. Plus he also shares you with a rando cursed Lizardman in the forest during his Forest Hunt quest. So I wouldn't know about that. Maybe you chose the option for him to tone down his kinky side lol. I encouraged my Rhot to always call my character a "sssslut" hehe.
Rhot actually has two encounters on the Forest Hunt, you just have to time it right. You, Rhot, and the enemy lizard have to step into the same tile together and it will trigger the extra event for Rhot.
Basically you end up seeing him beating up a lizard and you get horny and offer him a blowjob in the woods. While blowing him, the beaten up lizard wakes up and gets hard seeing what's happening. Rhot then pushes you back slowly until your ass ends up on the enemy lizard's cock... and well you can imagine the rest.