Sometimes a picture warrants a thorough explanation. That's not necessary with these photos. The faces say all you need to know. 

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Source: acidcow

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Source: imgur

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Source: deviantart

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Source: rebrn

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Source: memeguy

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Source: funigy

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Source: imgur

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Source: dailyhaha

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Source: keepbusy

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Source: onsizzle

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Source: imgur

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Source: imgur