Using 'smarmy' suggests someone is not genuine and can create a negative impression of the person described. His smarmy grin made me mistrust his intentions.
Pro Tip 2/3
Not Flattery
'Smarmy' is not simple flattery; it implies excessive sweetness or charm used manipulatively. The smarmy compliments felt more like a sales pitch than genuine praise.
Pro Tip 3/3
Evaluate Context
Consider the context; 'smarmy' often suggests that the polite behavior is out of place or inappropriate. His smarmy remarks during the serious meeting were distasteful.