Omg im gonna camp here
it's not exactly like you described but...
in this manga there are two occasions that they let people watch them have sex: https://www.mangago.zone/read-manga/the_prince_of_proctology/
and in this one it was unintentionally intentional where they had sex in the same room as mc's assaulter + pursuer cousin: https://www.mangago.zone/read-manga/mayday_mayday_mayday/
There's one scene in https://www.mangago.zone/read-manga/antinomy/..its exactly like you described
Already read the both of these but still thank you. (=・ω・=)
Thank you (=・ω・=)
Any yaoi/bl where the couple let an annoying character watch them have sex because he/she didn't stop pestering one of the mcs?