They have a talk!

Once they were cleaned up, Rias looked towards Issei, noticing he seemed a bit contemplative. "Master?" she asked him. "Are you okay?"

"Eh? Yeah, I'm fine," Issei replied.

"You sure? You seem like you have something on your mind," Rias noted as they grabbed their clothes and started to dress.

Issei contemplated telling her, before deciding to do so. "It's just that I felt a bit uncomfortable with the first time we had fun, and then just now, I felt amazed that I didn't feel that way again... like with you, I'm completely secure in how much I can trust you intimately, but would have a difficult time doing so with anyone else."

Rias blinked, before smiling. "Well, Master, it definitely helps that you know for a fact that I am completely loyal, and love being your sex ****, but also, Sex Genies and their Masters do tend to develop special bonds after the first time or two. However, I think I know why you might be hesitant to get close to anyone else again... it should be obvious really..."

Issei paused and considered, before realizing where Rias was going with this. "You think I'm afraid of another Yuma situation happening?" he asked, and realized that that was exactly what was going on. He had been trying to not think about the fact that someone had pretended to love him, just to kill him.

"Of course it left a mark on you, Master," Rias replied. "The worst thing about a betrayal is that it never comes from someone you see as an enemy. Someone gaining your trust, and even potentially your love, only to rip your heart out... that has to leave some scars," she replied, her tone full of sympathy. "You hesitate somewhat in your subconcious, because you don't want that happening again, but you know for fact that it couldn't possibly happen with me, so you don't have that issue with me and me alone, right?"

Issei stared at her, amazed at how she had read him better than he had read himself. "...I think you're right..." he admitted. "...that's going to complicate getting a harem if I'm subconsciously scared of having relationships like that again," he slumped.

"...well, Master, that can easily be fixed," Rias smiled, and Issei looked up, wondering where she was going with this.