What was the relationship between Saladin and King Richard I in the 3rd Crusade?

Although Saladin and King Richard 1 were opponents in the 3rd Crusades, they respected each other and had an interesting, unusual friendship. For example, Saladin gave King Richard I fruits and snow to cool his drinks when he was sick. Saladin also gave King Richard I two fresh horses when his horse fell during battle. King Richard 1 even suggested his sister to marry Saladin's brother.