Aguilera's Boyfriend -- The SAD Walk Out of Jail

Christina Aguilera's 25-year-old boyfriend Matthew Rutler has just been released from the pokey following his DUI arrest early this morning ... and he couldn't have looked any sadder.

Rutler -- still wearing the sportcoat he rocked last night --  was totally silent as he was escorted out of the West Hollywood Sheriff's Department.

He was whisked away by a waiting SUV ... probably to Christina's house ... where the two will have plenty to talk about.

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