Forgotten the title - arranged/forced marriage, initial neglect

Hey, I read a book a couple of years that was fantasy setting/arranged marriage, and the MC initially stayed in his room withering away for ages before the LI realized and coaxed him out. Short read, hurt/comfort, there was maybe a dragon (tbh I'm not sure cause so many I read have dragons haha) I looked through all the threads here but couldn't find it - it was short and sweet

Edit - there was a rainbow river as picnic site??