Party objects are the place to look when your Sims are planning a party or social event such as a wedding. Cakes to age up your Sims can be found here, as well as bars.
This cake is used to age up all Sims, except elders. Only Sims two days away from aging up can use the cake to Blow Out the candles. If a party is taking place when the interaction is made, a special cinematic will be triggered. The cinematics differ based on the Sim's age. Once the cake has been used (aka the candles blown out and the Sim aged up), Sims can Grab a Plate and have a slice of cake, which satisfies Hunger. Cakes will eventually spoil. If Seasons is installed, the cake can be put away in the refrigerator to be eaten later. After the cake has been used or has gone off, it can be thrown away. If more than one Sim is aging up, a cake for every Sim must be bought. A cake cannot be reused.
This is simply a decoration to add to the party theme. After some time, the balloons will pop, startling any nearby Sims. Popped balloons must be thrown away.
Multiple meals can be served from a buffet table, which includes salad, gelatin, and turkey. Each meal costs money to serve ($150 for turkey, $75 each for gelatin and salad). When Sims Clean Up the table, they can restock it. Like all food left out, it'll eventually spoil.
This cake operates differently to the birthday cake. This is used specifically for weddings. Only newlyweds can cut the cake. The newlywed who cuts the cake feeds their new partner a bite. After this, any Sim can help themselves to a plate. After the cake has been cut, it can be thrown away.
Drinks can either be blended or poured, but there's no difference to their effect. Sims can make one drink or several. Sims can also drink from the bottle, which satisfies Hunger and Fun, but Playful Sims get more fun from this interaction.
This object is used to marry Sims. Although the wedding arch isn't needed to marry Sims, using it unlocks a special cinematic, and allows the newlyweds to go on a honeymoon.