How many calories do you burn during a 30 minute sex session?

Not counting the foreplay, how many calories on average would you burn on a mostly intense 30 minute sex session. I feel just as exhausted as after i jog 2 miles, so am i burning about 300 calories? I couldn't find many serious answers on the net, so i asked it here. I just started doing some cardio, so i'm trying to figure out how many calories i burn a day.
You can tell me how many for foreplay too if you know what the average is on that.