Jayson and Lori have been teaching Ian to sign what he wants and he’s supposedly doing it in this video, but I’m not sure what the sign is. Either way, here’s a video of Ian with his Uncle Jayson.
Updated to add more description from Lori:
the signing he is doing is for more and please. more is touching your fingers together and please in the up and down on his stomach… it is suppose to be with just one hand, however, ian is doing it with both, same thing