There is no incest between the main couple in this...ML Eros is a god and son of Aphrodite and Ares meanwhile FL Psyche is a mortal princess of a small kingdom in the human world...
And even with side characters Aphrodite is the daughter of Uranus alone without mother after his genitals fell into the ocean (like Athena that was born from Zeus skull alone) and Ares is the son of Hera and Zeus just like Hephaestus.

Why does it look like some incest is going to happen, i mean i know that happens in greek mythology did not expect het manhwas for a female audience to do it though