He has NEVER matured, slowly, at first, then VERY rapidly, all of his friends and his brother got married and had kids, whilst Harry dithered, got passout drunk, dressed as a Nazi, picked up strange women and played STRIP SNOOKER in Vegas, etc.!
He had a slew of proper girlfriends, whom he treated indifferently and/or badly...so they quit him.
Finally, he wound up being just a THIRD WHEEL/a lonely kid looking in at "happy families", left without any louche pals with whom to have a hedonistic life with.
He even tried to get it on with Pippa, who spurned him, as she should have done!
Which brings us to Markel, whom he glommed onto, like a drowning man and a life saving piece of floating flotsam in an ocean.
Yeah, those things in your 2nd paragraph are what I was going to mention.
Ms Markle has her own sleazy history. The National Enquirer suggested she may have been married young and had that marriage annulled. No follow-up on that one. She then married on a beach in Jamaica. When she found out she was going to be on a CABLE TV SHOW, she sent her rings back to her husband by mail. He was shocked. Then she started working on Suits and met someone who knew Harry. Her plan to meet him and appear to be so much like him, started with her traveling to Africa on a ‘goodwill’ mission. He was lovestruck when he found that out! (Do we really think she would have made the trip unless there was something in it for her?) The whole ‘stars are aligned’ was charted without Harry’s knowledge and he fell into the honey trap. But as we’ve discussed, he wasn’t very bright to begin with. So, they probably are well ‘suited’ to each other, both self-absorbed narcissists. This train wreck will be interesting to say the least.