“Lounges IMO are not appropriate places to go for a date. “
Correct. In addition to the fact that hotel lounges are places where a lot of, er, uh, precursors to non-tzniut behavior occur, there is the issue that if the lounge is at all crowded, you are taking space from hotel patrons who are paying customers. This is a form of theft!
There are plenty of public parks and even indoor public spaces that aren’t privately owned and intended for paying customers.