A manga where an idol or tv celebrity who is dating someone under a disguise
The story follows the difficulty of a celebrity's life to maintain a romantic or fulfilling life

An example is https://www.mangaupdates.com/series/89n01s3/oshi-no-ko but instead of children, a boyfriend
I DON'T like BL or GL

Midori-kun ni wa Sawarenai
Peach Heaven

Yeah but is there ones where the artstyle is more modern?

The first recommendation from midlife_otaku was from a 2020 release o__o what type of art style are you looking for?

Oh my bad, the art style is like
https://www.mangaupdates.com/series/5qnw7cs/onnanoko-wa-otoko-no-tame-no-kisekae-ningyou-ja-neenda-yo
https://www.mangaupdates.com/series/bqa9hg2/kaichou-wa-maid-sama

Also the story i am looking for a darker subplot under the romance

Maybe you can try
Kasane (MATSUURA Daruma)
No Longer a Heroine!

Probs doesn't fit your preferred art style tho

Dude I have read Kasane long ago, my original manga topic was a double life of a celebrity which kasane doesn't match

i want a manga where the celebrity is hiding the fact that they are a celebrity cuz they are scared to be judged the the boyfriend/girlfriend

some more examples of my preferred art style is
https://www.mangaupdates.com/series/3xxulu3/07-ghost
https://www.mangaupdates.com/series/efg5tyb/kaoru-hana-wa-rin-to-saku
https://www.mangaupdates.com/series/8q91xb4/hagane-no-renkinjutsushi
Also i don't like webtoon

Kasane does have double life tho. Just not hiding a celebrity life. Also, I figured the art wasn't your cup of tea, but thought it was worth a shot since you said your wanted something a little darker

None of these are 'darker'

Sekai wa Nakajima ni Koi o Suru!! this is old so you probs wouldn't like it either
Charisma Doll "old"
Nousatsu Rock Shounen "old"
Utaenai Fairy "old"
Gekijou Komoriuta "old"
Teihen na Bokura no Jijou newer but they're not hiding from their significant other, but hiding their identity from everyone else
Sasada wa Okane de Oshi wo Daku

Good luck bro :v

Dude thank you so much
About kasane I loved the manga and it’s take on beauty and talent
I was just saying that comment earlier as I thought you didn’t understand what I had asked but anyway
thanks for the recommendation Utainea fairy and https://www.mangaupdates.com/series.html?id=24583529553