Hi Astro keen,I think the current relationship will be long lasting but there are some dramas along the way with a couple of cooling off periods possibly.
The cards:
Five of cups
Five of swords
Eight of cups
I think he might have kids and you don't really want them in your home environment except for maybe twice a year say thanksgiving and maybe when you are away visiting your mother or something, so generally you won't be interested in getting to involved with his kids - perhaps.
I think this comes down to you only wanting to spend your time and money or have your things used only by you, and him, if he comes up to par. His kids just won't be worth it enough to you - maybe.
In fact he seems to have a lot of connections including family and friends and you are not too sure of who you want to freely think they have a ticket into your lives. I think you could benefit though from becoming more generous with yourself to share with others. He can be a bit too open but for the most part, his connections will improve your life if you let it. I think you could even spend a lot of time with his mother/elder sister. And his kids feel like nice kids for the most part. But quite alien to you, like he is, in their unstructured approach to things - there's just way too much freedom of action and choice with him and his family etc, and this is quite unsettling to you.
All up, an opportunity for growth, you would benefit from being more open to meeting and sharing time with others, he on the otherhand would be affected by becoming more introspective and attentive to some of the details of living/life management.
You can definitely be a great combo, but it seems you have to allow each other's personality and likings to infiltrate the other, so that it seems that you become more like he is now and he becomes more like you have been. I don't think he's quite sure yet of what type of relationship you want, and isn't confident on how things will go as he is a quite fluid on direction and can change course if the environment is too rigid. Paradoxically, when the environment/relationship loosens, he becomes more rigid, stable and goal oriented. You may though have to play act initially at being open to spending time with others and going with the flow - it will really benefit you if you can do this though and will improve your vascular/cardio health.