most people will have had partners with other people before they settle down and get married, this is perfectly normal.

on most relationships they don't work out for whatever reason, and it's only one special person that we would actually settle down with, get married to, and have children with.

If this girl is so special, why didn't he marry her? He didn't, and he didn't even think she was even worth mentioning when he met you, he lied to you yes, but she wasn't important enough in his mind to mention that he had something with her.

I've been in relationships where my partner has talked constantly about their ex's, as if they haven't got other them yet, this happens when someone is still in their mind. If they don't mention their ex's it makes me think that they are no longer in their minds anymore which is a good thing I think.

I guess you have to remind yourself that he isn't with her, he chose you, and he chose you for a reason.