penetration interlock

Penetration where the thing that is penetrating (usually a penis) is in turn being penetrated (through the urethra if it's a penis) while inside. To avoid confusion, these will be referred to as the socket, being penetrated by the barrel, which is in turn being penetrated by the pin, using barrel connectors as a metaphor.

Usual scenarios

This can happen in a number of ways, so here's a list of common cases and how they look in practice.

Case #1: "The layered finger trap"

post #3975401 post #2437647

Not to be confused with recursive penetration, this one starts with the pin and barrel already mated with each other, before the socket closes around it.

Case #1b: "The deep-milking penis pump"

post #3153618 post #4638943

The usual scenario for a fellatio with urethral tonguing, where the pin is also inserted into the barrel first, with the socket closing around it afterwards, but both the pin and socket belong to the same person.

Case #2: "The table-turning surprise"

post #3790587 post #3747412 post #2514605

The most common one for vore, including unbirth_while_penetrated, but also a common infestation setup, and potentially usable for slit sex with gender confusion. This one starts with the barrel going into the socket, usually not expecting to be penetrated by a pin while inside.

Case #2b: "The greatest heist"

post #2294630 post #2512088

Similar to the above, but where the pin is actually removed from the socket in the process. This most frequent with infestation, but can also occur with vore as part of prey transfer, and possibly with something else like an egg.

Note the second example above, post #2512088, which uses partial vore to make the barrel the vagina of a second pred. While almost always the case, the barrel doesn't need to be a penis (or penis-like organ like an ovipositor or pseudo-penis).

Case #3: "Concentric mutual penetration"

post #1155768 post #4376248

A rarer situation where penetratration interlock is more or less exploited to allow both partner to fully penetrate one another to the hilt in a symmetrical manner.

Visual Guide

Name Diagram
Penetration Tunneling
  ════╗     
    ────┐ ▌ 
          ▌ 
     █████▌ 
          ▌ 
    ────┘ ▌ 
  ════╝ 
Recursive Penetration
  ════╗     
 ───┐ ║ ▌   
        ▌   
 ███████▌   
        ▌   
 ───┘ ║ ▌   
  ════╝  
Penetration Interlock
   ╔══════  
  ───┐  ▌   
        ▌   
  ██████▌   
        ▌   
  ───┘  ▌   
   ╚══════ 

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2024 5_fingers 5_toes absurd_res anatomically_correct anatomically_correct_genitalia anatomically_correct_penis animal_genitalia animal_penis anthro anthro_on_top anus aroused avian balls beak bear bear_tail becoming_erect big_balls big_penis biped bodily_fluids brown_bear butt claws cloaca cloaca_juice cloaca_juice_drip cloaca_juice_on_penis cloaca_juice_string cloacal cloacal_docking cloacal_penetration cloacal_penis close-up close_up_panel comic cum cum_drip cum_dripping_from_penis cum_in_cloaca cum_in_penis cum_inside cum_on_anus cum_on_balls cum_on_butt cum_on_ground cum_on_own_balls cum_on_own_penis cum_on_penis cum_on_self cum_on_sheath cum_pool cum_pooling cum_splatter cum_strand cum_string cum_while_penetrated cumshot deave digital_drawing_(artwork) digital_media_(artwork) docking dripping duo ejaculation erection fan_character feathered_wings feathers feet feral feral_on_bottom feral_penetrated finger_claws fingers fur furry_tail generation_8_pokemon genital_fluids genitals grizzly_bear hair half-erect hi_res hisuian_decidueye hisuian_form huge_balls internal internal_cloaca internal_penis internal_sheath internal_urethral interspecies kuruk_(character) larger_male larger_on_bottom leaking leaking_penis leaking_precum long_penis looking_pleasured lying male male/male male_anthro male_feral male_on_bottom male_on_top male_penetrated male_penetrating male_penetrating_male mammal mane mane_hair monotone_background mukinky multiple_scenes mutual_penetration mutual_penile mutual_penile_penetration nintendo nude nude_anthro nude_male on_back on_bottom on_ground on_top orgasm pawpads paws penetration penetration_interlock penile penile_penetration penis penis_in_cloaca penis_in_penis penis_tip plantigrade pokemon pokemon_(species) precum precum_bead precum_drip precum_from_penis precum_on_own_penis precum_on_penis precum_squirt precum_string precum_while_penetrated quadruped rear_view regional_form_(pokemon) round_ears sequence sex shaded sheath short_ears short_tail side_view simple_background size_difference size_play sketch small_ears smaller_male smaller_on_top standing standing_on_another tail talons thick_penis three-quarter_view toe_claws toes tongue tongue_out urethral urethral_penetration ursine ursine_genitalia ursine_penis vein veiny_penis wings
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2024 3_toes absurd_res accessory almost_fully_inside ambiguous_gender ambiguous_prey anthro anthro_on_anthro anthro_penetrated anthro_penetrating anthro_penetrating_anthro anthro_pred anus assisted_vore ball_bulge balls bed biped black_body black_ears black_fur black_hair black_nose black_tail breasts brown_body brown_ears brown_fur brown_pawpads brown_tail butt canid canine canis cock_vore colored countershade_face countershade_fur countershade_tail countershade_torso countershading cowgirl_position cutaway ear_piercing ear_ring erection eyelashes eyes_closed facial_markings feet feet_first female female_anthro female_on_top female_penetrated fluffy fluffy_tail from_front_position fully_inside fur furniture genitals glistening glistening_balls glistening_genitalia glistening_penis group hair hair_accessory hairband hand_on_butt head_markings hi_res hindpaw holding_butt humanoid_genitalia humanoid_penis internal interspecies kelova larger_anthro larger_female larger_male looking_back looking_pleasured lying male male/female male_anthro male_on_bottom male_penetrating male_penetrating_female male_pred mammal markings mask_(marking) micro micro_abuse monotone_hair multicolored_body multicolored_fur multicolored_hair multicolored_tail nude on_back on_bed on_bottom on_top pawpads paws penetration penetration_interlock penile penile_penetration penis penis_in_pussy piercing pink_eyes pink_hair pink_nose procyonid pupils pussy raccoon ring_(marking) ring_piercing ringed_tail semi-anthro sex shaded size_difference smaller_ambiguous smile soft_vore spread_butt spreading striped_markings striped_tail stripes tail tail_markings tan_body tan_fur tan_tail toes tongue tongue_out trio two_tone_body two_tone_fur two_tone_hair two_tone_tail unbirth_while_penetrated urethral_bulge vaginal vaginal_penetration vore white_body white_countershading white_fur white_hair white_tail wolf
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2_penises absurd_res animal_genitalia anus bodily_fluids cum cum_in_mouth cum_in_slit cum_inside cutaway digitigrade dragon duo european_mythology feral fridaflame genital_fluids genital_slit genitals hi_res knot looking_pleasured lying male male/male membrane_(anatomy) membranous_wings miriizah multi_genitalia multi_penis mythological_creature mythological_scalie mythology on_back oral oral_penetration oral_while_penetrating penetration penetration_interlock penile penile_penetration penile_spines penis penis_in_penis penis_in_urethra power_bottom quadruped scalie size_difference slit_penetration slit_play small_dom_big_sub small_top_big_bottom story story_in_description tail tongue tongue_out urethral urethral_penetration urethral_tonguing western_dragon wings zemble_(character)
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