Kim Zolciak's in a serious relationship -- her first since splitting from Kroy Biermann -- though it's not without its own drama ... 'cause she's dating the guy whose estranged wife subpoenaed her in their opwn $100 million divorce proceedings.
Here's the deal ... a woman named Jillian Green sent legal documents to Kim calling on her to provide a deposition in her divorce case with Kyle Mowitz -- requesting communications between them, and other information.