Starfire's needs override Raven's rational thought.

Well...one quick one wouldn't hurt, right? I mean, Beast Boy will be just as fucked up in fifteen minutes (and Raven had to admit she was probably giving Robin too much credit there) as he is right now. Raven smiled seductively.

"Mmm...that sounds very enjoyable Robin. Your dwelling or mine?" she purred. "Mine's closer," he responded, leading her off. As they entered the room, Raven began having second thoughts.

"This is so wrong," Raven thought, "It's like I'm making Robin cheat on Starfire with Starfire but actually me. And Beast Boy, he..." Robin kissed her, squeezing her ample alien breasts as he did so. "...can wait forever for all I fucking care. Gotta have him now!" Raven thought before pulling Robin's shirt over his head and kissing his chest. Robin took her top off. Damn! Starfire's boobs were even bigger then she thought! DD-cups at least. Shit, she was only a D. Oh well. For now, they were her tits. Star's breasts were so firm she didn't even wear a bra. He kissed her right nipple before licking it.

"Mmm...R...Robin, that feels great..." Her ability to fake Starfire's personality was fading with her growing arousal. Not that she gave a damn anymore. Right now, she had one thing on her mind. "Please, Robin...let me..."