public override void OnStartup()
{
    //Add these first two lines ONLY ONCE:
    base.OnStartup();
    base.AddComponent<Sims3.Gameplay.ObjectComponents.ItemComponent>(new object[] { false, typeof(sim) });
    
    //Add this line for each interaction you want to add:
    base.AddInventoryInteraction(TalktoMe.Singleton);
}

using System;
using System.Collections.Generic;
using System.Text;
using Sims3.Gameplay.Objects.Miscellaneous;
using Sims3.Gameplay.Utilities;
using Sims3.Gameplay.Interactions;
using Sims3.Gameplay.Actors;
using Sims3.Gameplay.Autonomy;
using Sims3.SimIFace;
using Sims3.Gameplay.Skills;
using Sims3.UI;
using Sims3.Gameplay.Objects;



namespace KolipokiMod
{

    public class TalkingTeddy : StuffedAnimal
    {
        protected Sim mRevealingSim;

        public override void OnStartup()
        {
            base.OnStartup();
            base.AddInteraction(TalktoMe.Singleton);
        }
        private sealed class TalktoMe : ImmediateInteraction<Sim, TalkingTeddy>
        {
            // Fields
            public static readonly InteractionDefinition Singleton = new Definition();
            private const string sLocalizationKey = "Gameplay/Objects/Miscellaneous/TalkingTeddy/TalktoMe";
            // Methods
            private static string LocalizeString(string name, params object[] parameters)
            {
                return Localization.LocalizeString("Gameplay/Objects/Miscellaneous/TalkingTeddy/TalktoMe:" + name, parameters);
            }
            protected override bool Run()
            {
                //Do the interaction here.                   
                base.Actor.ShowTNSIfSelectable("Hello", StyledNotification.NotificationStyle.kGameMessagePositive, ObjectGuid.InvalidObjectGuid, base.Actor.ObjectId);
                base.Target.mRevealingSim = base.Actor;
                return true;
            }
            // Nested Types
            private sealed class Definition : ImmediateInteractionDefinition<Sim, TalkingTeddy, TalkingTeddy.TalktoMe>
            {
                // Methods
                protected override string GetInteractionName(Sim a, TalkingTeddy target, InteractionObjectPair interaction)
                {
                    return TalkingTeddy.TalktoMe.LocalizeString("TalktoMe", new object[0]);
                }
                protected override bool Test(Sim a, TalkingTeddy target, bool isAutonomous, ref GreyedOutTooltipCallback greyedOutTooltipCallback)
                {
                    return !isAutonomous;
                }
            }
        }
    }
}

            private static string LocalizeString(string name, params object[] parameters)

            {

                return Localization.LocalizeString("Gameplay/Objects/Miscellaneous/TalkingTeddy/TalktoMe:" + name, parameters);

            }

        
        private const string sLocalizationKey = "Desecrate/Sims3Mod/TalkingTeddy";

        private static string LocalizeString(string name, params object[] parameters)
        {
            string key = sLocalizationKey + ":" + name;
            string localizedString = "";

            if (Localization.HasLocalizedString(key))
                localizedString = Localization.LocalizeString(key, parameters);
            else
                localizedString = name;

            return localizedString;
        }