It is not the about whether the seme knew or not if the uke was truly blind that matters.
It’s the fact that the uke finally opened up and revealed the truth. The whole lying game that the uke had going on finally came down. I think it’s more about the seme trying to love the uke after the one big lie in between their “”relationship”” has been erased. The seme’s intentions were never to know for sure whether the uke was blind or not but to wait until the uke came to the moment in which he became the most vulnerable by revealing that which he had been trying to hide for so long. Now that there are no secrets that the uke is hiding from him (that we know of), the seme can finally begin a new relationship.

I just read ch. 20 on Lezhin and confused. Isn't the seme already knew the uke isn't blind? But somehow he waited for the uke to confess so he could proceed with his "game"??
He said "I'm going to love you", what does that mean? Is he in love with the uke or he just likes the uke as his new play thing or a sex slave?? I'm super confused