It's really clear how much deeper his feelings are for Tia than the heroine. In the real timeline, he's wanted Tia to stop being 'interesting' and rely on, trust and cling to him like a real lover several times. He's felt jealousy and anxiety over Tia several times. He stopped seeing her as a toy a long time ago. Here, it's very obvious that, even with the bird chram magic, he only sees the heroine as a toy. The bird must've worked really hard in order to make a harem ending possible. Maybe it fried the prince's brain.