I mean, the guy had been doing this stuff for decades without any repercussions at this point. To him, he probably thought it was basically normalized. He really wasnt even trying that hard to hide his interest in seducing women with aphrodisiacs/drugs. Hell, years before the Cosby show even existed, he had a stand up bit in 1969 specifically talking about how, at age 13, he learned about Spanish Fly, an aphrodisiac that would make girls go super horny for you. He goes on about how, throughout his teen years, he wished he could find some Spanish Fly to slip into girls drinks, and how the first time he went to Spain as an adult he tried to find some for that purpose. By the time he told that "joke" in his standup, he'd already drugged and assaulted at least one victim in 1965.

Here's that stand up bit: https://youtu.be/LAorIG6MZnc?si=RKKtmGcWLfTf0KZn