An adaptor (16) for discriminating connection of an oral tip (14) having a length greater than 0.50 (12.70 mm) to a feeding line and for preventing sealed connection with a standard semi-rigid luer tip (20) having a length less than or equal to 0.50 in (12.70 mm) is disclosed. The adaptor (16) includes a duckbill valve (26) spaced at least 0.50 in (12.70 mm) downstream from a first open end (34a) of the body such that when an oral tip (14) is fully inserted into a connection port (42), the oral tip (14) engages valve flaps (48) of the duckbill valve (26) and opens the valve, and when a standard semi-rigid luer tip (20) is fully inserted into the connection port (42), the standard semi-rigid luer tip (20) does not contact the valve flaps (48) and the valve flaps remain in a closed position.
