Why not both?

I close my eyes as I unleash my cum into my little sister's furtile uterus. 'Resume.' I think, still a bit dazed. "John? John?! What the fuck are you doing?! Stop, this is wrong! I'm your fucking sister! Did-did you cum in me? John please no, I don't want to get pregnant!" She screamed and began to cry once she realized what I had done. 'Rewind.' I saw as her hand went back to her mouth and her face of angry sadness return to a look of bliss. It's not like my cum had returned to my dick, it more just disappeared and the feeling of me needed to cum returned. 'Pause.' I thought and went back to thrusting into her until I was on the verge of cumming. Once I was there, I pulled out and crawled over to her chest on my knees and jerked off until I came all over her face, hand and even got some cum in her hair. I moved and sat at the foot of her bed.

'Resume ' "John?" She took her hand out of her mouth and felt her face in one fluid motion before trying to cover herself "What are you doing in here? Why are you naked? Is this your cum?!" She asked quickly and angry. 'Pause.' Just seeing her sweet face covered in my cum started to make me hard again although I think I liked her reaction to me cumming in her pussy better. I got up and figured I'd see if anyone else was home maybe I could see what I could do to my mom? I looked at my watch and saw it was still early. I went back to the kitchen and fast forwarded to around when I woke up. When I saw Ashley walk in, I waited before resuming time.

She had a worried look on her face. "You okay sis?" I asked, playing dumb. "Yeah, I-" before she could continue, the doorbell rang