"Accepting plaintiffs' allegations as true, and according them the benefit of every favorable inference, as we must do on a motion to dismiss pursuant to CPLR 3211(a)(7) ( see Zumpano v. Quinn, 6 N.Y.3d 666, 681, 816 N.Y.S.2d 703, 849 N.E.2d 926 [2006]; Leon v. Martínez, 84 N.Y.2d 83, 87–88, 614 N.Y.S.2d 972, 638 N.E.2d 511 [1994] ), we conclude that plaintiffs have failed to state a cause of action for private nuisance against their neighboring defendants. Defendants' conduct in smoking in the privacy of their own apartment was not so unreasonable in the circumstances presented as to justify the imposition of tort liability against them (see Rodriguez–Nunci v. Clinton Hous. & Dev. Co., 241 A.D.2d at 340, 660 N.Y.S.2d 16). Critically, defendants were not prohibited from smoking inside their apartment by any existing statute, condominium rule or bylaw. Nor was there any statute, rule or bylaw imposing upon defendants an obligation to ensure that their cigarette smoke did not drift into other residences. Indeed, the law of private nuisance would be stretched beyond its breaking point if we were to allow a means of recovering damages when a neighbor merely smokes inside his or her own apartment in a multiple dwelling building. Since there cannot be a substantially unreasonable interference by smoking inside the apartment, there could not be a private nuisance, even if plaintiffs were to show that they had suffered some damage, annoyance and injury ( see McCarty v. Natural Carbonic Gas Co., 189 N.Y. 40, 46–47, 81 N.E. 549 [1907]; Newgold v. Childs Co., 148 App.Div. 153, 132 N.Y.S. 366 [1911] )."