Bethenny Frankel is mourning the death of her on-again, off-again boyfriend Dennis Shields. The 47-year-old "The Real Housewives of New York City" star paid tribute to Shields in an Instagram post Monday after the businessman was found dead at Trump Tower in New York. Frankel shared a photo of Shields lying in bed with her dog Cookie, who died in October. "Rest In Peace my sweet babies who gave me endless unconditional love. #nowandforever," Frankel captioned the post. Frankel's "The Real Housewives of New York City" co-stars Jill Zarin and Sonja Morgan were among those to express their sympathies in the comments. "I never thought I would be sending you condolences for your soul mate. I never met Dennis but he seemed like he truly loved you unconditionally," Zarin wrote. "Words won't console you but time heals. Don't erase but heals the soul." "Thank you for sharing this beautiful photo," Morgan said. "Cookie is with Dennis now. So many are sending you love and prayers through this very painful time." Shields died Friday of a suspected drug overdose, according to The New York Post. He is survived by his estranged wife, Jill Shields, and four children. Frankel and Shields were longtime friends who started dating following Frankel's split from Jason Hoppy. Shields praised Frankel in an interview with the "Listen Up Show with Michael Chadrow" podcast the week of his death. "She's great. She's a great mother. She's a great person. She's really, really smart. She is terrific in every way," he said of "The Real Housewives" star.