Responses
I don't exactly remember how but I think it was just god coming to them when they strongly desired something about sex or connected to that. Just like what happened when Seokjun wish to removed Yechan's dih. The difference in this scene was Seokjun wanted to personally meet god like that time Yechan's accidently kicked his balls.

How did Yechan and Muyeol meet god?
I highly doubt wither of them got kicked in their nether regions…