Yellow

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

Done reading .thanks

not just a love triangle but kind of they are doing it (smut)the 3 of them..

this is such a very rare trope,, they're usually found on one shots. based on stuff I've read—there is this one manhwa I read back then where the mc had like a different personality of himself that then manifested into a catboy and he was first in a selfcest situation with the catboy, then soon they did it all together with the ml ( I forgot the title of this one,, I don't even remember how I found it in the first place agshdjkdkd )

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

its not to much but i read "i will be your husband" and "three friend with benefit — boku no hero academia dj".If you find any more, please recommend them to me :'c

Right..i haven't read one yet..idk if the "boundary of illusion" is one of them..coz theres 2 tops and 1 bottom but the other top became a bottom..but kind of like that..i read a few like this but its always 2 tops and 1 bottom ...but i hope to know the title of what you mentioned...hope you will remember .. Hahah

I wonder if this is it "i will be your husband" ?

Thanks for the recommendation ...im gonna check now..

Sandwich!
https://www.mangago.me/read-manga/tachi_to_neko_docchi_ga_ii_no/