Right finally got through to the end of the thread.
OP I have been where you are right now. And I started a thread on it. And I had many of the same responses as you have had on here. And I've lived to tell the tale.
I'll tell you my back story. I was with someone for 3 years who was a total commitment phobe. Kept saying we'd get married 'some day'. In the end he walked out on me when I was 31, and I was left devastated but actually had a lucky escape (cos he was an arse). The reason I'm telling you this story is that some people upthread have said that your DP will dump you only to have a child straight away with some bimbo. That's what I thought would happen with my ex - but 5 years on, he's never even had a serious girlfriend, never mind any sign of having kids. So some men really are just commitment phobic.
Now on to my current DP and the subject of my own thread 2 years ago. I finally met the love of my life. So happy together I could barely believe my luck. He is divorced, so I understood that he wouldn't want to jump into marriage straight away. But then he told me that he'd had a vasectomy. He was adamant that he never wanted children.
I had to make the decision whether to stay with him and never have kids - or leave him at the age of 34 and take my chances.
He really is the love of my life, we are so happy together in every way - but I knew that if we never tried for DCs I would come to resent him and it would eat away at us and destroy our relationship anyway. But I was really careful not to push him into an ultimatum, because I didn't ever want to think that he was doing anything just because he was forced to.
So I ended up telling him that I loved him, I wanted us to have DCs and if he really couldn't commit to that, it would destroy us eventually so I might as well leave now while I have the chance to find someone else. I left him, and within a few days he came to his senses, realized how blinkered he was being and agreed to ttc. He had a vasectomy reversal a year ago, and we are now ttc just like any other normal couple.
While we were going over all of this, I went through everything you're going through. We loved our life, had great holidays, lots of freedom, and DP didn't want that to change. He sees lots of 'reluctant' fathers who don't seem happy, and he has a few single mates with no children who are happy. So he just couldn't see why he would change that. Once I explained to him that this is something I wanted with my whole heart and soul, and that we were so in love and happy together that it would be wonderful to create something that was a part of both of us, he started to come round. I explained that yes, our life would change, but it would change in wonderful ways that we can't even imagine.
I also talked to all of my married friends with children. Pretty much all of them said the same thing - that their DHs weren't really that fussed about having kids, sort of agreed to it in a 'yeah ok let's try' kind of way, then had a shock when it actually happened. In other words, there aren't many men out there who emphatically, enthusiastically throw themselves into desperately wanting kids. They're all wonderful fathers when it does happen, but their thought processes to get them to that point might be a little different.
Now obviously in your case you don't have the massive obstacle of a VR to get past. So what I would suggest to you is that you lay your cards on the table - explain to your DP how much you love him and want to create a family with him. Also explain that if he never agrees to it, it will cause resentment between you, and you don't want that to destroy what you have. And then explain that it could take up to a year to conceive anyway, so it's not like you're going to have an instant baby as soon as you agree to try.
As for the marriage thing - well I'm in the same boat as you there too. DP says he definitely wants to get married, but just can't think about it at the moment. I'm frustrated, but I'm not in any hurry to do it just yet either. As for those upthread saying this is 2014 and not 1950 and why don't you ask him yourself - yep, I've heard that one too. Well to me, the simple reason is that I've always dreamed of being proposed to. And i want it to be special. My sister 'told' her DH that they were getting engaged, and dragged him to a ring shop. 8 years down the line, she never stopped complaining that she never had a 'romantic proposal' and has ended up having an affair and leaving her DH. OK, I know that's not the normal situation, but that has heavily influenced me into thinking that if / when it happens for me, it will not be because I've pushed it in any way.