In , you'll find that friendships, romances, and starting a family are quite different from later games in the series. This makes it difficult to tell when you can select romantic interactions without being rejected and causing your Sims to lose points in their relationship.
However, there are ways to tell when you should try romantic interactions and general guidelines for how the relationship between Sims can be improved.
Since includes the Pack, Sims have two relationship bars under the portraits of the Sims they know in their relationship tab.
The top bar is the daily relationship, and the bottom bar is the lifetime relationship. Both bars affect which interactions the Sim will accept and how that Sim feels towards the selected Sim.
Once Sims have any time of relationship, the lifetime relationship bar increases just from Sims existing on the same lot for a period of time, even if they don't interact while on that lot, but increases in the daily relationship require friendly interactions.