Thanks for your query.Based on the facts that you have posted it appears that your partner has problem of Premature Ejaculation
Since he is 59 years old it is natural to have reduced libido and not getting hard erection compared to what one gets at young age
He can take medicine like Dapoxetine
along with phospodiesterase inhibitor like Sildenafil
to delay ejaculation .Please visit your family physician for dosage and prescription of the medications.