Letting Friends Try Champs??

So, it's understandable that fully sharing accounts so as to avoid buying things or working for any of the things in the game is against terms of use. My main question was whether it was against terms to allow a friend to play Co-Op or something like that on your account to try champions they may want to purchase on their account? I know free week is in place, but new players have so many questions and so much they want to learn, and I feel like it shouldn't be a bad thing for someone (like myself) who has put in a lot of time and money to acquire all the champions and such to allow a friend to try things out. I wanted to let a friend of mine use my account just to play some bot matches and try out any champions they thought were fun since they really want to get into the game, but I was worried that if it were mentioned I could be looking at a serious ban or possible account deactivation, so I wanted to bring it to the boards and see how everyone feels. It wouldn't be an all the time thing, just whenever they were really interested in picking up a new champ or something, until they get going on their account. All feedback is welcome of course, and I would definitely appreciate input from a red. :) Thanks guys!