I just bought this boy yesterday and my best friend and I were hanging out in his stall just giving him some attention. He kept doing this weird thing with his lip where he was sort of "motor boating" (sorry, best to way to put it!!) her chest. He was rubbing his lips all over her and anytime she crossed her arms or cupped her hands together he nosied them apart. He never bit or even opened his mouth. We thought at first he thought she had a treat and was "searching" her for it but he did it for over 30 minutes! Surely he would know by then she did not have anything?
(click on the link--anyone with or without facebook can look at the video)