I know this feeling.
Now I try for 30 minutes once she’s done and quit. Once it starts to turn into cardio and I’m sweating, there is no fun in it.
I was hanging with my uncle, he says one day his body did the same.
I don’t worry, it’s still fun, so who really cares if you get off. Shit you can watch porn for that. Plus after an hour I feel like I’m just torturing my wife. Cool thing is, she’d let me keep going if I really wanted, but a couple times she pretended to sleep and snore to be a smart ass, so if it doesn’t work in 30 I’m done.