hi you did'nt mention the age of your son still maybe he's not ready yet.try to pretend that it's ok for now but set a target date when he will be expected to stay in his own bed and prepare him for it. his birthday will work fine since you will be able to tell him that 3/4/5year olds sleep in their bed, so now on your birthday it's a big day when you'll sleep in your big bed cause now your not a baby anymore,etc... good luck!!!