Bay is showing some jealousy over this new mare, like she is a threat to his girlfriend (the pony) rather than a new member of his harem.... He runs interference between the new mare and the pony, and rushes the gate if the new mare and the pony get together. I am not sure he knows she is also a mare. He does this "comehere comehere comehere!, getaway getaway getaway!" thing and stays between the new mare and the pony.
At the moment they are still seperated, and probably will stay this way for awhile, till Bay stops lunging at her. At the moment, Bay and the pony have lost interest for awhile and she is having some hay in between pacing around.
