Mera felt her push every long inch of herself into Mera's core.  And then the bouncing started.  The sense of going up-down, up-down, combined with the feeling of cock sliding against her insides was a novel experience for the Terrestrial, one that she was not to soon forget.  What was more, for some reason, though embarrassment burned her face, she couldn't stop looking at their actions in the mirror that Yifa had them facing...she just<em>couldn't</em>.  Yifa's goal was certainly within reach if she kept on doing things like this.