Tell her to keep going

Ur balls are in agony and u can feel they are almost gone. You can almost here the bits of cartilage and blood vessels popping. Despite this your dick is rock hard and leaking precum. You sister clamps down all the way and your right testical catastrophically fails. Your left testical squirts free, severely damaged but still intact for now. Your rock hard dick explodes in orgasm as you scream in ecstacy and agony. Meanwhile your sister is also having the best orgasm of her life.