ADELE won Best Album at the U.K.'s BRIT Awards last night . . . then FLIPPED THE BIRD during her acceptance speech. She was angry because the host cut her off.  Apparently, her speech was running long . . . and he had to introduce the band BLUR, who was performing to close out the show. Afterwards, Adele apologized, and said the middle finger was for the show's producers.  She said, quote, "I was cut off during my speech but I wanted to thank the British public for all their support. "I was held up with my voice and troubles but the album kept walking without me.  I flipped the bird for the suits at the BRITS who cut me off.  Sorry if I offended anyone but it was for them, not for the fans."