how can a couple feel more happy and have longer SEX in bed every night?
Maybe you guys can go slower? Do diffrent things in bed.
I think foreplay is a really important part of figuring out how to have sex for a long time, and how to make the sex good. Start off slowly. Don't just go for quickies, which can become boring. Please each other orally and manually, try different positions, also try different locations, such as the bathroom, on the washing machine, in the kitchen, etc. And talk to each other about what you would like to try and be open to new ideas.
Variety is the spice of life and all that. That's perhaps truer in the bedroom than anywhere else. :)