'The Situation' is looking for the one that got away ... from the club

No happy ending here.

"Jersey Shore" star Mike "The Situation" Sorrentino spent Saturday night running around the city in search of a "gorgeous blonde" he met at Culture Club earlier in the night, a source told us.

The Sitch was "crushed" when the gal left him for a party at the Gansevoort Park Avenue, and when he searched the Gansevoort later, he had "no luck finding her," the source said.