What’s the name?

Hi I’m looking for a multi chapter black and white yaoi. They have a brotherly relationship and the older one is kinda tsundere. He had been putting this dick chastity belt thing on the younger one and is the jealous type. One chapter I remember is they are not allowed to have sex but the younger guy finds a way to masturbate with the dick belt and the older one is like uhm am I the only one pining for you and waiting for us to have sex?? And the younger one is like nah I miss you so much. The older guy tells him to show him how he masturbates with the dick belt and then they have sex. Cute story overall. Thanks in advance!