Hello! We have a new sink/faucet system. When it was put in originally, 3 months ago, everything worked fine. But we had to have our countertops replaced and a new sink was put in and a different plumber hooked everything up. Since it has been hooked up this last time the sprayer leaks after it has been used and the faucet is turned on. Frustrating to have a new faucet leak. This was not a cheap faucet either.
Thanks for any help!

Since it worked before the last plumber I'd call him back. The sprayer disassembles fairly easy by unscrewing from the hose at the base of the handle. The aerator also unscrews so I'd check both for bits of debris or scale.

It should be under warranty, have the installer return and warrantee his work.