The body remembers. No matter how young the child they do not "forget it ever happened". What might be a "one off event" for you is likely to bring a lifetime of dysfunction for the child. Whether you believe in God or not, He sees and either in this life or upon death you will be accountable. I understand your urge us strong, maybe even feels overwhelming but fight it. Take a cold shower, distract yourself in a healthy way, masturbate alone if you must but do not act, it’s never "ok", your moments of "pleasure" create the child a lifetime of Hell.
Sent from my Galaxy