Is he flirting or just doing his job?

UK based - ( we don’t tip) .
I ate at the same place regularly / weekly. They often run 20% off promotions but the manager often only charges me a very small amount of the bill and has wiped it completely on a few occasions ( £40+) . He always chats to me , has broken the physical contact barrier and I knows I’m single. Even if I ate with friends (female only) he discounts / wiped the bill. Is this good customer service or flirting?
Is he flirting or just doing his job?
Post Opinion