Possible Clues:

• Sensible to follow sourpuss, but not straightforwardly
• Irritable person, sensible, not coming forward
• Curve lifted over web is turned sideways
• Originally, basmati rice was served sideways
• Not straightforward grumble, sensible to follow up
• Sign's sensible yet not in a straightforward way
• Sour apple with sage to one side?
• Occasionally cars at BMW did skew sideways
• Laterally
• Not straightforward, but giving a sign to the initiated