Dakota does that too!! He lifts his head and nickers or whinnies softly when I dismount, because he knows it means we're done. He does with when other people dismount, too, because everyone in my lesson kinda dismounts at the same time, so he connects the sound of a rider's feet hitting the ground with the end of the lesson. So I know with him it's not a pain thing. XD
Every ride, good or bad, teaches you something new.