Your wife looks sensuously-attractive and strongly sexual, potentially. She has beautiful tits and gorgeous legs. She appears deserving of all the extra-marital sex she can handle.
Maybe if you introduce her to:
http://hotwifeletters.com/
(or suggest she enter HotwifeLetters dot com in her preferred search engine — and, of course, read it yourself), she will start to get the message. You and your wife might consider reading it jointly.
Your efforts along these lines will need to be tempered, of course, by the need for "social distancing" during the current coronavirus / COVID-19 pandemic. You might consider proceeding by setting it up as a mutually agreed-upon game, with your wife pretending to be your hotwife and you pretending to be her cuckold husband. This could lead to your times in bed becoming more intense, and your wife beginning to view herself (conceivably) as a hotwife-in-waiting. And, it could lend increased interest to your times together if you are in an area subjected to "stay at home" orders.
Please try to stay well.