S.I.
when my son was that age he completely refused to use the potty... unfortunately he learned the harder way but we had him completely potty trained in a week. we told him that he didnt have to use the potty but if he made a mess he had to clean it up by himself. so everytime he made a mess thats exactly what he did. he made a mess about four times before he realized that he hated having to clean up after himself. after that it was smooth sailing. one tip though make sure that you go over whatever he had to clean up to make sure its all gone. just dont let him see you do this. good luck hope this was helpful.