You can have a group of 8 sims maximum, your sim, their date (only 1 sim allowed for reasons to follow), and up to 6 guests. Goals still count when done alone or with guests, so don't necessarily have to be done with the date if you find out they dislike it.
The sim picked as date will be the sim in the reward photo with the initiating sim. Other dates can be added as guests, but won't be in the photo.
Guests can also be non-romantic company.
So this system allows for:
> Chaperoned dates (for teens, period gameplay or different cultures)
> Poly dates (additional partners come as guests, but won't be in reward photo)
> Safety Friend dates (you, or they, bring a pal just in case)
> Double/Triple/Quadruple dates with other couples
> Family-friendly dates (dating sims bring their kid(s) along too)
> Possibly (can't test yet) pet-friendly dates (like a Dog Park date with a Dog Lover and your/their dog(s))
> Chaos causing (bring along an ex or current lover, so they react to your date)
> Any combination of the above
There are also Friendly Hangouts that can be customised like the Create a Dates. These require 1 guest and up to 6 additional guests for the max of 8 sims. These are good for one-off group outings that you might not want to make a Club for, and are a great way to build a friendship quickly. I went from ~50% Green Bar to ~90% Green Bar in 1 Gold-level Friendly Hangout.
Oh, and I forgot to add that due to Create a Date/Create a Hangout being new Events, they can be scheduled on the Calendar like any other Event. Also the Difference between a Get To Know You Date and a Romantic Date are the Main Goals of each: Socialize (any socials) for GTKY Dates and Romantically Socialize (any romantic socials) for Romantic Dates.