Dear Romy Luna,
I started my relationship with Deep Creek Hot Springs 36 years ago when my wife was pregnant with our first child. We started our kids going to Deep Creek when they were babies and they continued to hike with us on up into their teens. We told them that people dress for whichever culture they happen to be visiting, for example, beach wear is not appropriate for formal functions and vice versa. The culture at Deep Creek is clothing optional so whatever the participant wants to wear, be it a business suit, swim suit or birthday suit, it's OK. Our kids were always at ease without clothes until they approached their teens and then wanted to don swim togs. Clothing optional applies to everyone and what our kids preferred as they matured was OK with us.
It's sounds like you and your husband are rational thinking folks, as are the high majority of the people you will meet at the springs. Based on my experience I'll bet that your trip we'll be a great one and soon you'll be regular visitors to one of the world's natural wonders.
Please write after your day trip and let us know how things went.
Cheers!