The Bravo star spoke with ET's Leanne Aguilera at the NBC Upfronts in New York City on Monday, and revealed which guests took full advantage of the late-night show's on-set bar.
When asked which celebrities were the most tipsy on WWHL, Cohen exclaimed, "Wow, I mean, how long do you have?"
The 49-year-old host then started naming names, adding, "Ricki Lake, Rosie Perez, Jackée Harry, Regina King [and] me."
Cohen also claimed that Jenny McCarthy and husband Donnie Wahlberg hooked up following their appearance on the show, and confessed to asking a few unnamed guests for their phone numbers. He went onto recall to ET the time Mariah Carey showed up late to WWHL.
Despite all the shenanigans that may go on behind the scenes, Cohen expressed his gratitude for getting to do what he loves.
"Watch What Happens Live nine years later is still a really happy place for me," he shared. "In nine years, you go through peaks and valleys, but it's been a good peak for a while and I'm still having a great time before every show. I'm very grateful."