Eight weeks after fertilization, the foreskin begins to grow over the head of the penis, covering it completely by 16 weeks. At this stage, the foreskin and glans share a skin layer that fuses the two structures together, called the balano-preputial-lamina (BPL). This is normal.

Normal foreskin development from conception to adulthood
At birth, the foreskin is almost always fused to the glans. During childhood, the foreskin and glans gradually separate, a process that may not be complete until late puberty or into the twenties. The average age of first foreskin retraction is 10 years. Some foreskins never retract, and this is normal, too.