A sex act in which a character inserts their penis into another character's sheath/foreskin. If both characters possess sheaths, mutual docking is possible and likely.

• While frequently confused with penis in penis and slit_sex, the three are distinctly different sex acts.

• urethral
• urethral_fingering
• urethral_penetration
• penis_in_penis
• cock_vore
• docking
• sheath_penetration
• slit_play
• slit_penetration
• slit_sex

Not to be confused with:

• Dock - Where the tail meets the rump