Tsundere Hime-sama ga Inran Hatsujouka! ~Ninshin Suru no wa Noroi o Toku Tame Desu wa! ...Aan♪ Jubojubo Atama no Naka made Hibiichau♪~

One day in the park a princess was under attack by an evil spirit. It was like some sort of fairytale!
The protagonist jumped it to save her, but not before the demon possessed him with lust and it affected her too.
She wants your sperm inside her! It's the only way to exorcize the lust!

[Modified from DLSite English]