sensei didn't 'only' care about his lower half tho.. in my opinion he's really serious, but he acts like he doesn't care.. he let the uke to choose because he don't want to force the uke to be in a relationship with him.. but, he wait for him to see if the uke will run after him, and the uke didn't
Sensei is narcissistic, manipulating and only cares about his lower half.