Personally I think saying this was a mistake. You're pretty much never going to gain another person's respect by telling them they should respect you...at best it makes no difference, but more often it lowers their respect for you.

IMO, use the opportunity to figure out how to deal with a large unwieldy opponent, don't worry so much about 'teaching' him how to do his part if he's not receptive or not appearing to find your advice helpful, when you get into that situation ask Sensei for help dealing with a large opponent who moves this way (if Sensei feels the need he'll show the uke something too), and otherwise just train with him, unless you feel unsafe or feel that he is going to get hurt. And especially, don't waste your time worrying whether your partner respects you or not.