s not real possible even if the kitten showed symptoms of
ringworm, unless your boyfriend was in very close contact, like sleeping with it every night
and cuddling a lot. Even then it would most likely show up on his body near where the kitten was, it wouldn't show up on his feet!
However, if the kitten shows no sign (scratching, scabs, missing fur), then it doesn't have ringworm and there is not chance of passing it on.