OP,
I'm nearer 60 than 50, and my libido doesn't seem to have slowed down much.
I was in the opposite position to you. My XW didn't want anything except (very very occasional) piv, always at night, and always in bed, and it always followed the same procedure....
I wasn't allowed to touch her sexually, and (far far TMI), but I dreamt of being allowed to play with or go down on a woman... Sex over a table or using a chair or in fact anywhere sounds amazing.
It sounds like he has (I'm sorry to say) lost interest a bit. There could be a number of medical reasons for this. Is he overweight? Is he taking any regular medication? Has anything changed with him physically in the last few years?
According to a friend
, there are condoms that have a numbing agent in them, that can help a guy last longer, if you are willing to use them.
Get the dildo. I can guarantee it will last longer than him, never be too tired, or not interested in you, and will do whatever you want it to do!