Sex if done correctly is alot of movement very quickly for a decent amount of time burns alot of calories for awhile. Happy to inform. (and it makes you happy helps with heart health and even blood sugar (proven) happy to help)
You burn calories doing anything including sex depending on the duration of course it could be a mini workout.
But then diet plays the major part on weight/ fat loss.
Its also good for the mind releasing endorphins...thou its also wise to take precautions!
If your male after a while your body can become drained of testosterone and workous become harder especially weight lifting.
Sex is a workout...BUT
comes with extra added responsibilities if not done correctly or with the proper precautions...like any exercise...lol