I'm bipolar, have an extensive family history, was diagnosed when I was 23 after having an affair and leaving my wife (that marriage broke-up). I'm now 35. I've had two manic episodes since, both involved affairs. The affairs accompanied other typical symptoms-- sleeplessness, enhanced creativity, wild energy, increased spending, being hypersocial, grandiose thoughts, and a ridiculous level of alcohol consumption. With this last episode, I had been off meds for several years, thinking that I was able to manage the condition due to my knowledge of and experience with the disease and by attempting to cultivate healthy daily habits, etc. Yeah, right. The mania snuck up on me without me realizing it and before I knew it, my partner of eight years had moved out and I was talking about forever and ever with another woman. It was almost like having a dual consciousness-- somewhere in the far recesses brain I knew I was out of whack, but my thoughts were all over the place, constantly changing, and I wanted to push the fantasy with this other person as far as I could. I felt this uncontrollable urge to cultivate as much energy and intensity with others as possible, and I pursued and obsessed over multiple women in addition to this affair. It took me a couple of months to come down and I wanted my partner back more than anything when I did. In each of these instances, the seemingly intimate and intense exchanges in those affairs were completely illusory, and I had absolutely no feelings for the person after the episode was over, except for the guilt of getting them involved in my sickness. Thankfully, my partner took me back-- I'm on meds, stopped drinking, and am determined to do everything I can to decrease the possibility of a future episode. Like others have said, it's highly likely your partner will return to his normal self soon. My partner is also bi-polar. Double the drama. Hypersexuality is one of her symptoms, too, so I've been on the other end of things as well. Both times that it has happened with her, she thought she was in love with someone else for about three weeks, and then she came out of it. She's been completely horrified by her behavior both times and views it as nothing more than a symptom that lead to an absurd mistake. Hope that helps :).