When we first started, I was super adamant about him not cumming inside me. But one time we were going at it and our mom came home. She didn't know I was there and looked in on my brothers room, he had moved a pillow beside my face and pulled his blanket over us and said he was going to pretend to sleep, and for me to lay as flat and still as I could. I heard the door open and he was pretending to be asleep. I could hear my mom on the phone talking to my uncle saying, "ya, he's out, bla bla bla, we'd be coming over after me and my dad got home..." She just stood there talking. Doug would make little like slow pushes into me occasionally. I thought so he wouldn't get soft, but he stared down at me and whispered "I'm sorry". Then I felt him get super hard, then his cock jumped once, then again, then again. But the third time I felt a rush of warmth and like alittle jet hitting me deep. He was all the way in me and I got scared. I mouthed 'no, stop' but he just stared at me with his mouth open. Then again, and again and again I felt it. Each pump squirted harder each time. My mom was still talking, I assume just leaning in the door way or out in the hall, but my heart was racing and all I could think about was my brother, 17, in me, 13, and he was pumping his cum right against my cirvix. The thought and feeling, knowing his sperm were rushing up inside me so deep made me cum. Doug's face was so serious as I felt myself gripping down on him, then I felt like my pussy was milking him, griping and rippling all along his cock. After what felt like forever, I heard my mom walking away, Doug still inside me growing smaller. He pushed up and looked between us. He slowly popped out of me with a wet slurp sound. I got up, grabbed my stuff and went to the bathroom. I locked the door, started the shower and just sat on the toilet for like at least five minutes. Thinking about how we almost just got caught, the fact that my brother had just inseminated me, a week before my period of all times. Then I felt a drip slip out of me. Then more, i looked down and it wasn't alot and very clear. I started thinking I may be okay. I felt it. It was super slippery and i got so horny thinking about it all again. I used my hair brush and got off again. As I pulled it out, it was covered in gobs of thick cum. I got scared again and jumped in the shower and started washing myself, fingering myself trying to get it out. There was so much. I was nervous the whole week after. We didn't even talk about it really. I realized a few days later I was 3 days late starting my cycle. I talked to my friend, and told her it was my neighbor. She said it's actually normal the first time to skip a month after. So I waited. My brother and I played some after, just touching and licking mostly. I'd give him head and he started asking me to let him finish cause he wanted to watch me swallow it. He told me how he liked knowing his cum was still inside me and how horny it made him after. It was like a month later and I told him about the shower and missing my period. He got scared and bought be a box of pregnancy test. He said to do all three. When I did, two were negative, one positive. We were so scared. He said he was going to buy more but I said wait till my next cycle in a week. He agreed and we talked about it. The more we talked though, the more he told me how much he liked it. I told him how horny it made me. We started doing it again. A week later... Nothing. I told him and he said he needed to think. For two days he didn't say anything. Then 3 days late, I had my period. Talk about relief. He was so happy we did it like five times, like in the shower of course lol. We still do it, 3 years now. But we watch our timing more carefully lol.