When I have the kimura locked in from the bottom of half guard, sometimes my opponent will grab the arm that's being attacked with his other arm and shoot both arms down between his legs, essentially straightening his attacked arm.
After thinking about it for a while, I figured if I would keep his arm close to my body, I could prevent him from doing this. Then I thought about ways to keep his arms pinned to my chest from underneath and still bent. I thought of these two;
keep my chin on top/over his elbow or
actually use my thumb to grip his wrist instead of the way i'm doing it now (no thumb on his wrist)
I haven't actually tried these two techs yet, as I was just thinking about it after practice. What do you think of these two solutions and is there any other ways to keep his arm bent from the bottom and finishing that kimura? Thanks