I noticed the place yesterday (also didn't have time to stop in). I haven't figured out if this is the one in the Cityxguide or usaadultclassified ad (or both, or neither).
Sign on the store is Golden spa, 302-274-2165, on Foulk at Silverside (company set up in late Nov.)
Cityxguide specifies Foulk Road 302-522-9169, Grand opening Dec 21
usaadultclassified.nl specifies Golden spa in Delaware, says to email for phone and address.
This ad has a very explicit listing of services, and the porn photos included are also very explicit. (And certainly not any providers or customers in Delaware. I haven't emailed them to get their information yet.)
https://usaadultclassified.nl/ads/golden-spa-asian-girl-nuru-full-body-massage__1577642945-38489602
I may stop by the store next month; I'm not as sure about responding to ads with detailed sexual services and photos.