Can't baby-proof the baby!

Scott and I spend the day together twice a week, just the two of us. It's really fun for me to play with him, and teach him stuff and just enjoy my child. We're doing ok, even with my growing belly. Mostly.

There's one issue we have. During diaper changes Scott likes to kick and laugh his head off. And he likes to grab anything he can (sometimes). This is incredibly frustrating and makes changing him difficult. And then, it's equally difficult for me to wash his hands after. 3 more (increasingly difficult) months of this s*it.

I can baby proof the house so he can run around. But how do I baby proof the baby from himself?