No, this would not work. If you're logged into the game on one of your linked platforms and then your other linked account signs in, you will be kicked from the game with a WEASEL error on the first platform. Also, for your friend to be playing your Titan, they would need to be logged into your account. I strongly recommend you don't give your account credentials to anyone, as that could be a major security risk on top of the possibility for a ban.
[url]https://help.bungie.net/hc/en-us/articles/360049517431[/url]