Deja vu all over again

After the I'm-in-love-with-a-stripper-instead-of-Michelle episode with the last guy in the circle of friends that I dated, you would think I'd learn my lesson. Not so. I'm a little slow on the uptake when it comes to guys. Enter Alex.
Super hot bike racer boy with the Lance Armstrong body and model face. Tall, crack free, and down with the brown. Cha ching! I'd been giving him the eye ever since we met, but he had a girlfriend. I respected that. His girl was mad cool! She showed me so much love every time I saw her. It was like we were old friends. She was all, "Hey girl! How are you doing? How have you been? Let's get a drink! Let's shake it fast!" I loved it when they would come hang out. That's why I asked about her when I randomly ran into Alex on the streets of Venice in June. He said they'd broken up and gotten back together and that she'd moved into his flat. I told him we had to get together when we all got back to London. He agreed and we parted ways.
Fast forward two months to the going away party for our mutual friends who were moving to Australia. I say, "Hey! Nice to see you, Alex. Where's Mimi (his girlfriend)?"
"We broke up," he replied.
"That's ok," I told him. "You'd just gotten back together when I saw you in Italy a couple of months ago, so I'm sure you'll be back together again soon."
"No, this time it's permanent," was his response.
The conversation stayed friendly and flirty for a bit until we were interrupted by my crackhead ex who HAD to talk to me. I excused myself only to discover that coke face didn't want much. This scenario repeats at least thrice more with him pulling me away from Alex to talk in the bedroom, bathroom, kitchen... anywhere Alex wasn't. Suddenly Mr. I'm-in-love-with-a-stripper only wants to chat me up. Jealous much?
Side rant on jealousy: Ok, let me get this straight, coke face. You date me for three months and put me at the bottom of your priority list; only calling on Thursday to make weekend plans. Next you leave me for some crooked toothed, fake boob having, stupid ass stripper with whom you claim to be hopelessly in love. Then almost six months later, when you've only seen me once since our breakup, you have the nerve to be jealous when another man pays me the slightest bit of attention at a party. WTF? You have no such right! Get over yourself coke face!
Anyway, several glasses of wine later, Alex and I are alone on the couch while everyone else chats in the kitchen. The party starts to clear out and our hosts offer to put us up for the night. We agree and stay up until 6am. We exchange info as we part ways the next day and vow to see each other again. Timing is bad on both ends and we blow each other off for about two weeks before we get together again. We have a great dinner date Tuesday night and plan to go out again on Saturday. We go to dinner and a gig on Saturday night and end up having a slumber party. After breakfast on Sunday morning, he suggests we go to the Thames Festival. We walk along the river all afternoon taking in the sights and smells, eating, drinking, and being merry. We decide to stay and watch the fireworks around 9pm (we got there around 3). Around 8:15 he tells me he agreed to meet his ex twice removed (not Mimi, the ex before Mimi). I knew they were still close and she's also in our circle of friends, so I agreed to go too. Apparently it was a statement, not an invitation. He told me that he thought it would be weird if I went, so he'd just go and call me later to tell me what they were doing because he didn't want her to be on her own. Then he left.
Um...HELLO! Now I'm on my own jackass!
He called and texted to apologize later that night, but I wasn't taking calls. We spoke the next day and he explained that he was still sleeping with her and thought it would be weird if he showed up to meet her with me as he and I had been smooching and holding hands all day. I told him that I was through. I've been down this road before and I know where it leads- just ask coke face. This is deja vu all over again! I can't believe I didn't see this one coming though!
I have the worst dating karma ever! Either I'll marry and be blissfully happy until the moment of my death, or I've done some dude from my past so wrong that he's on the brink of suicide everyday. While my dating adventures do make for great reading, they make for a pretty pathetic love life. Dating in London is WAY worse than dating in the US. Any tips on breaking this curse?