Hello and welcome,
Thanks for your query.
Let us first discuss the age factor, a man in his 50's is going to notice a change in his performance, though not always, but there is a chance his performance is a little different from what it was earlier, in this case, with his previous partner.
Another thing we should discuss is the possibility of tiring him out with
oral sex and in turn reducing his performance during sexual intercourse. What I would advise would be to refrain from oral stimulation or making him climax through oral sex, and leave most of his energy for the real thing.
This would help in ensuring a long standing erection.
Next would be to keep him constantly stimulated. At times, while one partner is concentrating on the other, he/she is neglected and might lead to a less stimulated state.
Why don't you start the session with him concentrating on stimulating you, followed by you stimulating him, which would ensure an erection, immediately after which you can perform sexual intercourse.
Please do not misunderstand him, the technique is always the most important thing in a sexual relationship and during intercourse. Always keep an open mind and I am sure he will show you physically how sexually attracted he is to you.
Asking him questions would only lead to him feeling more conscious and even frustrated as he is not able to show you how sexually attracted he is to you. Instead allot more time on sexually stimulating him, and boost his confidence.
I hope I have succeeded in answering your questions, you could write back to us anytime for further clarifications.
Best wishes.