I'm thinking it would be frugal, and therefore thoughtful, of you to take a shower together every night before your dh goes to work. I'm assuming everyone is home, and therefore you have someone to keep an eye on the baby.
Sex noises are well-concealed by a shower. In fact, I think you need to buy your parents a low-flow shower head, with a stronger spray. It saves water, too, and of course it's a bit louder than your conventional shower head.
The babysitting should be arranged to last through and including the time it takes you guys to get dressed.
And damn, girl, you are in TENNESSEE! There is a National Forest in your backyard!
Other than that, it's not the end of the world, so keep reminding yourself that this is only temporary and jazz your alone time up by talking about all the different places and ways you'll be doing it in your own house, eventually. And oral. That's really quiet and sneaky, like the other posters said ;)