If i remember right it was some sort Arabian theme or some sort of prince Seme where uke is possible held against his will and made to stay with the seme.
Uke is made to serve the seme wine while seme is having a bath but ends up slipping and spilling the wine. Uke gets told to be more careful because floor was marble or something. Later finds out the wine was laced with poison.

Any help is much appreciated

Maybe it's in this list.

Thank you for helping, I couldn't find it on there sadly

3 in this look like they fit: https://www.mangaupdates.com/series.html?category=poison&genre=Yaoi&perpage=50

Fujoshis rule!

thank you for the help, but it doesn't seem familiar