all his life Sherlock has been laughing and omegas with their heats and alphas with their ruts.
he never envied his alpha brother for his so called 'dominant nature' and instead revels in the freedom being a beta gives him.
He has never had any sexual urges and considered himself above all that.
Until he met alpha john watson. he slowly starts developing feelings for him and starts to question his decision to stay celibate.
then, one day, his flattmate goes into rut and sherlock is the only one around...