Twitter API related question

Hello Friends,

I have a doubt.

I have integrated Twitter authentication in my application. At the initial I was just storing just the twitter username, but I have a requirement where I’ll need to store a Twiiter user token and secret key as well, for the new user who is authenticating I am able to save it. But I am not sure how to save for the existing user

. Like there is only one way which I can see is that, I’ll need to ask the existing user to authenticate with twitter again.

OR

Is there any way like it should save it auto without asking user to authenticate again.

Thanks
abhis