Just do nothing, and use it for masturbation aid.

Despite your feelings, you don't do anything to confirm the validity of the video. Instead, you just quietly save the video onto your phone, intending on using it as masturbation aid for later. Real or not, you can't help but find yourself utterly aroused at the video. Mash getting hammered and slammed in by a dark colored man had turned on feelings inside of you that you didn't really know. You felt a bit distressed that your Kouhai was getting fucked and pounded in by another man, one she had only just met recently compared to the months of hardship you and Mash had, but... watching her discarding it all just for a stranger stirred heartstrung feelings in your chest that only made your cock stiff and hard.

After cleaning yourself off, you head out of your room, only to meet Medb standing there. Seems like she was waiting to see the results of her first work. "So~ How'd you think about it? Did you enjoy relieving yourself to the show of your little underling being taken from you by a real man?" She lewdly grinned afterwards, cupping your balls even out here in the hall!

"Fufu~ Hard as a rock. I take it that you enjoyed it quite a bit~ This first time is free, but every other time you'll have to pay me some materials. So.. do you want to continue?" She asked, gently stroking and rubbing against your crotch.