Makes sense. It depends on the situation. There is no exact science to it nor a right or wrong way to go about it. I do believe that once you reach a certain age (30+) especially without children, you kind of appreciate the peace that comes with that lifestyle (adulthood and freedom).
Sleeping around with randoms bring a lot of unnecessary drama; especially when you are at a point in life where you are sharpening your skills. Being unfaithful brings a lot of unknown into the equation, specifically, demand mostly on your greatest asset which is time.
Chances are if you chose your lady, there is a reason you did. If those reasons are still important, stick with her. If not, play the field.
Hope that helps.