In the Parallels menu, go to Devices, then USB and you can check and uncheck your printer there. When I want to print in Mac, I uncheck or disconnect it from Parallels; and then when I want to print in Parallels, I connect/reconnect it back to Parallels. See if that works.
Glad it works! If you have Parallels in full screen mode, you can right click on the Parallels icon in the dock and connect and disconnect the printer there, too.