A.J.
He will figure it out...it's the rare baby who would rather starve than take a bottle. I run a daycare and run into this dilemma now and then with new babies. Some tips:
1) Make sure the bottle (and nipple) are warm - slightly warmer than breastmilk even.
2) Make sure nipple is the right flow size...usually it will say size 1, or easy, or beginner, etc.
3) Put a little sugar water on the nipple (this is actually used as a breastfeeding trick too) so they will start sucking.
4) When introducing bottle, don't let it be when he's starving and screaming already...do it in 1-2 hours after last feeding so he's hungry but not yet crying.
5) They seem to do better when it's not Mommy`feeding the bottle...aka, when there isn't a boob in their face that they'd rather have. So may take it just fine for the sitter
6) Just stick with it...takes a little work but he will catch on. 3 days should be plenty of time.
GOOD LUCK!