'Squi' is Chris Garrett, the guy that Ed Whelan named in the twitter thread that he later deleted.
The guy that lived close to the country club, showed house plans, etc.
Ford dated Squi (Garrett) and seems like might have had a thing with his brother also, kind of hard to tell from her testimony.
https://www.washingtonexaminer.com/opinion/columnists/is-july-1-1982-party-key-to-christine-ford-allegation-against-brett-kavanaugh?_amp=true&__twitter_impression=true