When I was between 7-10 years old, my sister (who is 4 years older) initiated sexual contact with me, primarily 'practicing kissing.' I felt uncomfortable but didn't know how to express this or refuse. There were specific incidents where she would restrain me to continue kissing, saying it was 'practice for boys.' Later, when I was older, there was another incident of prolonged kissing that I agreed to, but have felt shame and disgust about for years. Given the age difference and dynamics, would this be considered child-on-child sexual abuse (COCSA)? How do I process these experiences that still affect me?

Thank you for sharing your experience with us. What you're describing—a significant age difference between you and your sister, and her initiating activities that made you uncomfortable—is understandably causing you to question whether this was appropriate behavior. While only you can label your experiences, I will try to provide some information and perspective to help you do so.

At ages 7 to 10, you were in a stage where you were just beginning to understand personal boundaries and relationships. Your sister, being 11 to 14, was entering adolescence with a more advanced understanding of sexuality and social interactions. While some level of curiosity and exploration can be normal among siblings close in age, the scenarios you described involve a notable age gap and instances where you felt forced or unable to express your discomfort. The fact that you remember feeling that it was wrong, feeling uncomfortable, and being unable to say "stop" indicates that your boundaries were not respected. 

It's important to recognize that as a child, you depended on your sister to respect your boundaries and to model appropriate behavior. Any situation where a child feels coerced or is unable to consent can be concerning. The feelings you've carried for years are valid and significant. These emotions often arise when personal boundaries have been violated, even if the actions didn't involve overt physical force.

Whether or not this fits a specific definition of child-on-child sexual abuse (COCSA), what's most crucial is how these experiences have impacted you. Consider reaching out to a mental health professional who can provide support and guidance as you process these feelings. A therapist experienced in working with childhood experiences can offer a safe space to explore these memories, help you understand the impact they've had on your life, and assist you in healing from any lingering distress.

Remember, you were a child in these situations, and it's not your fault that you felt unable to stop what was happening. You deserve compassion and support as you navigate these complex emotions. You're not alone, and help is available if you choose to seek it. Thanks for trusting us with this.