I’ll Do That Marriage is a Manga/Manhwa/Manhua in english language, Drama series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Lilianne McKellion, the girl who wanted to avoid a bad end, willingly went to the insomniac emperor in place of her sister, Laelin.

She is tasked to help the sleepless emperor, who was cursed by a witch, by using her ability to induce sleep whenever she touches another person’s body with her lips.

Can Lilianne survive being with the emperor, ‘Kael Rue Kaldorf?’