Op user:
I am not sure I see the issue with the bad knee. Instead of putting her weight on her knee and her lower leg, she can sit with her full weight on her partner and "lodge" her sole along the body of her partner. Less stress on her knee more weight on her partner making her more happy.
Apron Double Belly can share the issue with her knee if she chooses to do so.
My experience has been that if the woman is able to be on her knees, she can do much more riding. It is the movement of the penis inside the vagina that gives pleasure. If the woman has her legs straight to avoid pressure on her knee, you are correct, there is more weight on the man, but it would be impossible for him to thrust. She might be able to move side to side but it would be difficult for back and forth.
When the woman is on top on her knees, she can also lean forward and put her nipples in my mouth while we are engaged in intercourse.
If your BBW or SSBBW wants to be on top, you might try using a chair or bench. The man sits and the woman can straddle him while standing. This does eliminate a lot of pressure on her knees. The trick is finding a chair/bench that is the right height.
Reverse cowgirl (woman on top facing away from the man) on a chair/bench is also good. The woman can hold on to another chair or table for support. If her tummy is large enough, the feel of her tummy on your legs, along with her riding your cock, is incredible.
Bottom line, give it a try. Different positions are exciting. If it doesn't the first time, try another time or two. If it does work, enjoy! What works with one partner may not work with another. However, they are all worth trying to see what is best.
