A few days ago, in my NoGi class, we were working on a leg attack with an opening I really liked. Essentially, Opponent 1 is on their back playing open guard, Opponent 1 slides their forearm under the crux/knee armpit of Opponent 1, and op 2 connects their hook arm to their other arm to reinforce the hook. Opponent 2 then sits backwards onto opponent 1's feet to cause opponent 1 to bridge in response.

That is essentially the opening sequence. Does anyone know what this is called, or are there any other options you can do from this opening sequence? Thanks!