Depends on how good you are and if you have an agent.
Just click on the Romance interaction and keep clicking on all romance things to do until propose going steady shows up!
Going Steady was created in 1969.
Going Steady - album - was created in 1989.
Singles Going Steady was created in 1977-11.
Going Steady - 1958 is rated/received certificates of: Finland:K-16
Going steady means they are going out on a regular basis, and they are not dating anyone else.
When you click on either of the Sims who are going steady there is an option to break up, just click that.
It theoraticlly depends how fast it is. E.G if it was going at a steady 100kms (62.5 miles) it would take 170 years E.G if it was going at a steady 200kms (125 miles) it would take 85 years.
Going out, going steady and dating
Going Steady - 1958 was released on: USA: February 1958 Finland: 19 September 1958
About fifteen years and 6 months if you would like to calculate how long it is going until it cancels.