With a learner's permit how old does the panger have to be?

I live in Washington state I am 19 years old and am hoping that my 20 year old boyfriend can teach me how to drive. I have my learners permit but I am not sure if it would be considered improper use of a permit if he taught me. I found some stuff about the penger being 21 but i'm not sure if that is only for minors. Does anyone know?