If you’ve ever come up for air after a particularly rambunctious romp in the sack wondering how many calories you just burned, a new wearable sex tracker has your answer – along with several others you didn’t know you wanted to know.

In essence, Lovely is a "smart" sex toy - a Fitbit for your penis, if you will. 

The tracker fits around your penis and measures your sexual activity, from the number of calories you’ve burned, to the number of thrusts you’ve completed, to the overall intensity of your session. Linked via Bluetooth, a smartphone app measures all this data and grades your session (Bad, Fair, Good, and Cool Ranch), then recommends new sex positions “to help you have even better sex next time.”

The silicone one-size-fits-all sex toy also vibrates for added stimulation during the deed.

“Over two years ago after particularly intense night with my partner we started wondering how many calories we just burned. I replied that there must be an app for that and actually started looking for it, but found nothing,” Jakub Konik, Lovely co-creator, told TechCrunch.

“I did some more research, talked to sexologists, industrial designers and engineers, and realized that we could create a device that not only tells you how many calories you burn during sex, but actually understands your desires and helps you to pursue them.”

The designers press that the tracking software is built for couples of all orientations.

“It doesn’t just have to go on a penis,” said Reid Mahalko, a sex and relationship expert attached to the project, in a promotional video for Lovely.

“You can put this wearable on a dildo, you can put it on your fingers, you can use it on a toy on yourself. It’s really only going to be limited by the ideas that you come up with.”

Lovely’s battery lasts for seven hours without vibration, or two hours with. You power it back up by placing it in a wireless charging cradle.  

The device was being funded on Indiegogo through last year, and is now available to pre-order for $99.

h/t The Huffington Post, TechCrunch