IENFH-023 - Promised my sister 'just touching', but couldn't hold back... ended up raw dogging?

My sister came to me worried about being pregnant by her married boss. Trying to comfort her turned into a heated kiss. She tried to resist, saying 'we're siblings,' but eventually gave in to my advances. The promise of 'just a handjob' shattered instantly. Seeing her wet and ready, I couldn't help but slide it right in! 'Wait, it's inside?' The forbidden act has begun, and there's no turning back.