Jinx
The Foul
Sugar Rain
Even if you don't love me
The Moon-Painting Alchemist
A well known love affair
Mary Jane
Daily part time job (alternative title : Gig of the day)
Work Love Balance
Groan (not on this site, you can find it on Zinchanmanga and some other manga sites though)
The Rogue Prince Is Secretly an Omega
I will add more in replies if I can remember more. Happy Reading.
Finder
Raion Gotoki no Kuni Kara
Mother's Spirit
Ookami wo Karu Housoku
Rent Boy
Painter of the Night
A Painter Behind the Curtain
Steel under Silk (Alternative title : The Blade and Flower)
Willow Love Story
King's Maker
Where the Wind Stays
Palace of Bardo
Royal Servant
The Servant / Employer
Two Empires, The Slave Of The Empire
Saturday's Master
Penthouse XXX
Big Apple
Dream-Like Lie
A Paramour
Wolves behind bars
Tourou no Ori (Alternative : Mantis Cage)
Hina wa Mitsuiro no Koi ni Torawareru
Hugo
It's Not Like That (Gangto)
Kiss me, Liar (+ Kiss Me, Liar - Special Episodes)
Kiss the Bride
How to Chase an Alpha (Alternative title : How to Snag an Alpha)
The Alpha's Bride
The Fox's Thief Marriage
On or Off (Prequel of "Work Love Balance")
Saezuru Tori wa Habatakanai
Dangerous Convenience Store
Erv
2020
Fever
Be, Be
Hellen
Vesper
Reunion
Formless
An Abyss
Black Sun
Risky vice
Morpheus
Dial Again
Macguffin
My Master
The Abyss
Irreversible
In the deep
Half Goblin
Private Call
Gorani Jeon
Limited Run
Solo for two
Kamu Otoko
Kuchuu Teien
Spinel(baekji)
Flip the script
Muri Marriage
Cry Me a River
Mermaid's egg
My Rei of Light
Crush and Burn
Sleepless Night
Blood and Love
Night of Lindon
Come and Take!
I won't get eaten
Plin's Love Juice
Sweet not Sugar
Sunshine Shower
Stranger in Mirror
Scratch Romance
Kappa no Yomeiri
Kyuujitsu to satou
Liquor & Cigarette
The trapped Beast
The Tyrant's Reign
Kouguu no Omega
Futari no Maharaja
Cherry Doll Scandal
Tsumi To Kuchizuke
Boukoku no Emanon
Into the Rose Garden
Stockholm syndrome
Plum Blossom Shade
Razoku no Hanayome
Sahara no Kuro Washi
The Color of the Night
Oni no Esa ja Arimasen
Weather Forecast Killer
Soko wa Sawaru Natte!
Stage of the Dark Souls
Fate Between Neighbors
Stars Seeing Nightmares
Kowarekake No Omocha
Silence (AKIYAMA Koito)
Royal Wedding (Bamilssi)
Memories Of Your Breath
Beta Count Has Changed
Torokeru Chouai Celluloid
Senya Ichiya Romanesque
Go forward with the rebels
Yokujou (IWAMOTO Kaoru)
The Bride of Amber Vanilla
Asagao wa Yoru kara Saku
Uncomfortable appearance
The Sound Of Coral Blooming
Awa ni mo Narenai Koi Nara ba
Run Away, Assistant Manager Ha!
Hetakuso Inma ja Dame Desu ka?
Aware na Beta wa Koi wo Shiranai
Taiyou to Himitsu (Secret and Sun)
Idol Debut with an... Arabian Prince!?
Secretary Gwanggongs survival diary
Why Are You So Kind To Everyone Except Me?
This Wasn't The H Life I Imagined After Reincarnation!
The half-demon dragon knight is obsessed with the Markgraf
Stranger than Friends (the second couple matches your requirements)
Quick Transmigration: Addictive Relationship
Bouncer and the bride who ran away
Wish you all the best (alternative on other sites : Prey)
First call 1ć The Virgin Surgeon is About to be Married to a Young Yakuza!ć
From Guideverse -
How that Guide is loved
Conditions of a guide
Over the paradise
Guiding Light
Profundis
Guiding Hazard (Seme is the guide and uke isn't that skinny but compared to Seme he sure seems like one since Seme is taller and very muscular)
I have intentionally avoided mentioning any BL from Beastmen genre (one of the partners, mostly Seme, looks like an animal like Wolf or Tiger but their bodies resemble that of a human and they can walk and talk just like humans) since it's not everyone's cup of tea. Do let me know if you want me mention some of them cause they match your requirements, as most of the times the uke is skinny and the seme is taller and more muscular.
Love History Caused by Willful Negligence
Literally every yaoi ever
Exactly what I was think while listing this.
But I had to avoid mentioning some good mangas just cause the seme isn't buffy/muscular (both seme and uke are regular built)
A Painter Behind the Curtain
Painter of the Night
Temperature of Skin
Sunset in Water
Mary Jane
Hellen
Good Hunter & Bad Prey (Actually, check out other mangas from GwangGong Apartment complex series as well. They're all Fire! )
recommend me some buffy seme and thin uke please :((((