Back in the late 90s, he had a holographic girlfriend - younger than him - named Stunner. Since Supervillains aren't ever allowed to be happy, she remained trapped in her morbidly obese body as well as a coma, and has not been seen since. It's a pity, because she was a nicely tough variant on the tired old Harley Quinn archetype, and a comment on body types/fashion, etc. And, if she was still around...we wouldn't have the Doc interrupting the wedding of a woman two decades older than him who he tried to wed for the nuclear reactor she was inheriting that one time.