Am I About to Be Scammed – Upwork??

I recently found a knowlegeable developer on Upwork and I've hired him for a few small jobs which he's refused payment for so far. (He says he usually just works larger gigs and not to worry)

I was telling him of my Fb Ads troubles with getting my accts flagged/disabled and he told me about a $$ making opportunity and basically asked me if he could use my developer account on Upwork to get more projects/income generated since they won't allow him to bill clients if he's already got clients…

Am I About to Be Scammed – Upwork??