I love the awesome looks of these girls but it needs a story. Why is the zombie horny? Did he defeat them in combat so he's fucking them? Did someone put a spell on them to make them want to fuck the zombie or did they have to fuck the zombie to protect someone being held captive? You have wonderful art skills but if you can't come up with a story you may need to find a partner to write the story while you do the drawing and animating.