Reverse Cowgirl

I just need advice. My SOs penis curves up toward him so cowgirl is usually fine but he wants me to do reverse and I've tried a couple times and i can't do much, it will slip out or be uncomfortable for me and hurt. I see videos where the girl is leaning forward while reverse cowgirl but that seems impossible for us. Any tips on how to make it more comfortable for both of us? Usually I'm sitting up or leaning back with my knees down and I've tried squatting also but I'm running out of options.