My 11 week old wont take a bottle?

I have recently started going out on the weekends so i drop my son off at his grandfathers house to be babysat. I will typically be gone for 5 or so hours. He refuses to take the bottle, he would rather have his pacifier! Normally he eats every 2.5 hours so i know he must be hungry. He wont take the bottle from anyone, not me, his father...no one. We have tried every different type of nipple. Any suggestions on how I get my son to learn to take the formula and the bottle?