At the end of the day though any relationship can end. The mere fact that the couple themselves are separated is testament to the fact that there are no guarantees in any relationship, and that long-term means nothing.
And there are ways of making introductions. The more formal and arranged it is the harder it is going to be, because you feel that pressure for things to work from the very beginning.
Personally I think the longer you leave it the harder it is, because introducing kids into the mix changes the dynamic of a relationship completely. personally I know several people who waited a long time to introduce kids and the relationship ended within weeks because the relationship changed completely, whereas I know plenty of people who introduced kids within a couple of months and they stayed together, because nothing changed in the relationship.
Personally my DS met my now DP within 6 weeks. Not because I chose it, but because my ex gave me an ultimatum, either I introduce DP to ex or he would, and then he showed up with ds when DP was here to
collect something ds had forgotten.
So we went out on the next weekend, DP was introduced as my friend, they got on really well and still do.
And ex was pissed off because he believed that DS would be upset and he knew that that would have caused me to end my relationship. Instead DS went back to his and talked endlessly about the nice time he’d had with us.
We’re still together 8 years on. Had I had a multitude of casual relationships my attitude might well have changed as things went on, but we’re talking a first relationship here, and IMO every situation is different.