Requirement for guest to add a plus one (or more)

Hi, I have worked out how to set up events etc for a logged in user. My client is now requesting a feature that will allow the registered user to be able add his/her guests to the event.

For example, the registered user clicks "I'm attending"

They are then asked if they are bringing any guests, with a couple of fields to input names and emails.

The new guests will be seen in the RSVP list.

Is this possible?

Many thanks