gypsy - Wiktionary: Etymology

From Old English Gypcyan, French gyptien (meaning Egyptian, gypsy), from Latin Aegyptius. See Egyptian.

Like a right 'gypsy, hath, at fast and loose, Beguiled me to the very heart of loss.

Like a right gypsy, hath, at fast and loose,
Beguiled me to the very heart of loss.
Shak.

Fast and Loose - Wkp:
I hadn't wondered about the expression - I just thought: he plays fast & loose with the truth ~ that is, recklessly.
but, huh: Fast and Loose is a cheating game played at fairs by sharpers

[ phrases.org.uk - Play fast and loose: This derives from an old deception or cheating game in which something that appears stuck (fast) easily becomes loose. ]

Sharper - Wkp: A sharper is an older term, common since the seventeenth-century, for thieves who use trickery to part an owner with his or her money possessions. Sharpers vary from what we now call con-men by virtue of the simplicity of their cons, which often were impromptu, rather than carefully orchestrated, though those certainly happened as well. The 1737 Dictionary of Thieving Slang defines a sharper as 'A Cheat, One who lives by his wits.' In the nineteenth-century, and into today, the term is more closely associated with gambling.
Sharpers were romantic figures in the eighteenth-century, valued as imaginative figures for their perceived social independence and ability to create new social networks of gangs.

yeah I find the love among thieves romantic... and I'd like growing up with the feeling that life is a river, that possessions come & go, identities can be assumed and discarded, all the personal institutionalizing can be manipulated like unimportant elements...