Solutions for tenant who is "loud" in bedroom at 2am?

[Jessica F.]

I own a duplex and I occupy the 2nd floor. I have a tenant (single female) on the 1st floor who has only been there a few weeks and has sex quite loudly around 2am when I am trying to sleep after putting in a 12-16hr workday. The noise is quite loud and it is always wakes me up from my rest or does not allow me to fall asleep at all. The entire home has hardwood floors and yes, the walls are quite thin but I can deal with everything else except for the loud noises at night. It seems like I can hear everything and it's worse when the headboard and the bed starts moving as well.

Someone suggested putting carpet in the BR to muffle sound but the tenant is already moved in so that's not really an option for me at this point. I don't know if my walls are thinner than a typical home but I don't recall getting such an earful with the previous tenant who lived there. 

Please respond if you have any ideas or suggestions on how to deal with this situation or what I can say to express to the tenant in a kind way (if at all possible) to be courteous of your neighbors especially in the middle of the night and that I can hear everything so it would be great if she could keep it down.

I am looking for solutions, not sarcasm.

Thanks for your time.