Potty Training

so my bf has a 2 1/2 yr. old and we've been trying to potty train for months now. His mom says that when he's with her he pees on the pot and daycare says the same thing but he will not pee on the pot when he's with us. He will literally say he has to pee so we take him to the bathroom and then he won't pee. 2 minutes later he pees in his pants.... we do the same things with him as his mom but he just doesnt want to. anyone with ideas how to help him?