leer at (someone or something)
To stare at someone in a cunning, malicious, or lustful manner. There were these two guys leering at us from across the bar all night long, so we never really felt at ease. I just leered at them as I plotted their company's downfall.
leer at someone
to gaze at someone flirtatiously or with lust. Why are you leering at that woman in the bikini? Stop leering at me!