Scáthach, the mighty Heroic Spirit, stood in the center of the Stimulation Room within Chaldea. The room, which was typically filled with various machines and devices designed to help Masters and Servants recover from their battles, had been transformed into a beach scenery. The walls were now adorned with images of sandy shores, clear blue waters, and the bright sun shining down. The floor had been covered with soft, white sand, and the air was filled with the scent of saltwater and sunscreen.

Scáthach, wearing a revealing purple swimsuit, noticed her Master, Ritsuka, sitting on a beach chair, looking stressed and tired. She approached him and said, "Master, you look like you need a break. Let me help you relieve some of that stress."

Ritsuka looked up at Scáthach and replied, "Scáthach, I appreciate the offer, but I have a lot of work to do."

Scáthach smiled and said, "I know, but a little relaxation never hurt anyone. Trust me, this will do you wonders."

She then proceeded to undo the top of her swimsuit, exposing her massive breasts. Ritsuka's eyes widened as he took in the sight of her. Scáthach then sat on Ritsuka's lap and began to massage his shaft in between her breasts.

Ritsuka let out a groan as Scáthach continued to massage him. He said, "Scáthach, this feels amazing, but I can't let you do this. I have work to do."

Scáthach stopped massaging and looked at Ritsuka with a serious expression. She said, "Master, I understand your responsibilities, but you need to take care of yourself too. You have been working non-stop for days, and you need a break. And I am offering you one."

Ritsuka hesitated for a moment, but then he nodded.

Scáthach got on all fours and moved her bottom to the side, revealing her wet pussy to her Master, Ritsuka. The sight of her exposed flesh caused Ritsuka's shaft to immediately grow hard once again.

Without hesitation, Ritsuka moved behind his Assassin Servant and thrust his cock inside of her. Both Scáthach and Ritsuka shuddered in pleasure as he began to move his hips, filling her completely.

As Ritsuka continued to thrust, he also reached out and grabbed Scáthach's massive breasts, fondling them as he fucked her. Scáthach moaned and cried out in pleasure as she felt her Master's cock hitting all the right spots inside of her.

Ritsuka, lost in the moment, began to pick up the pace, fucking Scáthach harder and faster. Scáthach, in turn, pushed back against him, meeting his thrusts with her own. The two of them moved in sync, their bodies working together in perfect harmony.

Ritsuka reached down and wrapped his hand around Scáthach's throat, gently squeezing as he continued to fuck her. Scáthach's eyes rolled back in her head as she felt her Master's hand on her throat. The added sensation only served to heighten her pleasure, and she moaned even louder.

Ritsuka continued to fuck Scáthach for several more minutes, before finally reaching his climax. With a loud groan, he filled Scáthach's pussy with his seed, causing her to shudder in pleasure.

After they both finished, Ritsuka pulled out of Scáthach and collapsed onto the sand next to her. The two of them lay there, panting and sweating, completely spent from their intense lovemaking session.

Scáthach turned to Ritsuka and said, "Master, that was amazing. I needed that."

Ritsuka smiled and said, "I'm glad I could help, Scáthach. You always know how to make me feel better."

Scáthach smiled and leaned in to kiss Ritsuka, before getting up and saying, "I'll leave you to rest now, Master. But remember, take care of yourself."

Ritsuka nodded and watched as Scáthach walked away, her perfect ass swaying with every step she took. He couldn't help but feel grateful to have such a caring and attentive Servant by his side.