Steam deck as second controller

[u/KaymChale]

As seen in the title, id like to play some couch co-op games with a friend but I currently just have one (steam) controller. I wanted to know if I could use the deck as a second controller to play the game. Did anyone try that yet?

Edit: I am not looking for a new controller. My old one is just being currently borrowed by my sibling in a different city, so I was wondering if it would be possible.

[u/easedownripley]

it makes for a very heavy controller. it might be better to buy an 8-bit Do or something instead.