Responses
I feel like the whole setting was actually more like old Japan regime time when men would have to go to parents to ask for their daughter's hand in marriage.
It was common to propose when they were still of young age and wait to take their hands after coming of age.
It was weird but not really.... taking into consideration that he waited 13 years for the uke to become an adult and everything that happened was consensual, I really can't judge. I think it is completely fine in this instance and the love they both had for each other were honestly really pure and cute. The thing I found weird was the parents reaction to the seme when he asked for their permission to their child's hand like how were they so calm lol?!?!?!