My Dog Peed In My Bed!!!?

MY DOG ONLY USES POTTY PADS! THIS MORNING I AM LAYING IN A PUDDLE OF HIS PEE AND IT’S ALL OVER ME LIKE HE PEED ON ME.! MY ITALIAN GREYHOUND IS HOUSE TRAINED AND GOES TO THE BATHROOM, TO DO HIS BUSINESS. WHY TODAY?? THEN HE”S LAYING RIGHT NEXT TO ME, WHEN I WAKE UP. I HAD MY FRIENDS DOG ON BED YESTERDAY. BOTH MALE, COULD THAT BE WHY. I’M AT A COMPLETE LOSS