Total of 47 new interactions!

Emotional Support:

These 6 interactions will only be available when the Target Sim's current mood is one of the base game negative moods. You will then see this menu pop up under the Mega Interactions>>>Friendly Menu.
These interactions will give you both a notification and a buff for both the actor and target sim.
If the interaction fails, both Sims will get a Sad moodlet.
The moodlets are the same across all 6 of these, but the dialogs will vary.

Venting:

These are similar to the emotional support interactions, except you get to complain about specific topics that are bothering your Sim! Find a good, supportive friend, and let out your frustrations!
Unlike the Emotional Support interactions, these will be available for your Sims (child-elder) at all times. They are also not relationship dependent.
If the interaction succeeds, the Sim that is venting can get one of 3 moodlets, assigned at random.
The listener Sim may get 1 of 6 moodlets. 3 are positive (Proud, Sensitive, Happy) and 3 are negative (Anxious, Sad, Sad). They are more likely to get a positive moodlet than a negative one, but both are a possibility.
You get 8 of these

Chat:

These are your basic "Discuss Topics" type interactions, except now they are split by topic. You get 21 different options of subjects you can talk about, including sharing travel stories, talking about sports, etc.
These interactions are available for all Sims (child-elder), regardless of relationship level.
These are very simple and do not give you any notifications or buffs, with a few exceptions like the how have you been interaction, for example:

Compliments:

If you have the Romance Interactions mod, this is similar to the compliments there, except these will not build romance. You get a total of 12 compliments.
Any of these compliments will give a moodlet to the receiver, which will be the same for all compliments, so that your Sims don't get overwhelmed with moodlets even if you choose to compliment
You will also get the notification pop up with the conversation between your Sims, so you can see their reaction.

The One Where They Are Friends