Bls

https://www.mangago.me/read-manga/ookami_kun_wa_osowaretai/

https://www.mangago.me/read-manga/love_sick_dog/
https://www.mangago.me/read-manga/foul_s_start/
https://www.mangago.me/read-manga/punks_triangle
https://www.mangago.me/read-manga/neon_sign_amber/
https://www.mangago.me/read-manga/fangs/
https://www.mangago.me/read-manga/kimi_to_nakayoku_naritaina/

Smut
https://www.mangago.me/read-manga/zero_lover_1/
https://www.mangago.me/read-manga/junai_drop_out/

The ml for this one is shitty, but the mc is the one of the few manhwa characters with snakebites:
https://www.mangago.me/read-manga/that_sexapparition_mgs/

https://www.mangago.me/read-manga/first_of_summers/
https://www.mangago.me/read-manga/given/
https://www.mangago.me/read-manga/grieving_you/
https://www.mangago.me/read-manga/cover_up/
https://www.mangago.me/read-manga/love_in_orbit/
https://www.mangago.me/read-manga/stigma_marloong/
https://www.mangago.me/read-manga/shima_chanchi_no_tsugaijijou/
https://www.mangago.me/read-manga/neon_sign_amber/
https://www.mangago.me/read-manga/mods/
https://www.mangago.me/read-manga/nights_before_night/ (spin-off of MODS)
https://www.mangago.me/read-manga/the_secluded_sorcerer_wants_a_peaceful_life/
https://www.mangago.me/read-manga/see_you_my_king/
https://www.mangago.me/read-manga/here_u_are/
https://www.mangago.me/read-manga/the_mountain_branches_dream_of_goblins/

https://www.mangago.me/read-manga/mobius_strip/

Nipple piercing:
https://www.mangago.me/read-manga/cash_or_credit/

I haven’t really read this one, so I’m not sure, but I think I read some comments mentioning nipple piercings?
https://www.mangago.me/read-manga/prison_dogs/

kill the lights