To be honest, I saved my seeds in my Google drive or Google sheet all my seeds are place in there and it is easy to use and for me it is the safest place to store my seeds.
Well, you are a honest dumb. If I h.ck your Gmail I may access all of your accounts, if there is smth inside you could loose what u got.
An advice for you, keep your wallets at a safe place such as paper wallet, cold wallets etc.
What if he encrypt the document? Wouldn't that make it safe since you hack his gmail, you need axcrypt password?