Luann de Lesseps has issued an apology after she was allegedly “kicked out of a piano bar” for drunken behaviour. The ‘Real Housewives of New York’ star insists she is recovering from alcohol addiction and admitted she slipped up after a video surfaced of her “belting out jumbled versions of songs” and being booed at Townhouse gay bar in the Big Apple. In a social media post, the 56-year-old reality star penned: “This week, after a regrettable incident, I was faced with the truth. “I want to apologize to the staff at Townhouse and anyone else I may have offended by my behavior. “Clearly, my st…