I have been seeing someone for a couple of years now - since May 2012 - both 45, never married, I have primary age children, he has none, he stays at mine Saturday nights for the last couple of years.
My children don't see their father so I have them constantly, occasionally my Mum may babysit or do a overnight babysit.
Most 'dates' are spent doing stuff with the children and my boyfriend has mentioned this in a manner that suggests he's getting fed up with it now.
He's also said that my 5 year old son needs to stop barging into our bedroom when he stays otherwise he doesn't think he can stay anymore.
My son is going through a developmental stage at the moment where he's testing out his independance I think - his sister went through the same about that age - he's moving from being a clingy mummy's boy to a more independant young boy.
I've tried explaining this to my boyfriend but he seems convinced my son is manipulating me (of course, children are capable of that, I know, it's normal enough) but keeps saying my son is pushing him out, or being deliberately antagonistic because he feels threatened by him.
I'm convinced it's just a stage he's going through. So we have a difference of opinion here.
My son has known him since a baby. They both call him Daddy of their own choosing, as in all respects he acts like a father, treats them accordingly, takes us places together as a family and so on.
They do also make the distinction between him and their bio father who they haven't seen or heard from in 3.5 years.
My boyfriend had an unpleasant, abusive experience with his stepfather when he was a toddler and he does refer to this when discussing my son, his stepfather thought he was being too clingy with his mother and used to physically haul him off her and threaten him. That's my boyfriend's experience of stepfathers.
He has also been a stepfather himself for 15 years, where he went into a relationship with a woman who already had two teenagers, neither of which accepted him as a stepdad but were happy to utilise him practically.
So,...he hasn't had a lovely time in this arena as you can see.
I'm not looking for a deconstruction of him, as he is a universally perceived good man, and we have been through a couple of trying times together such as miscarriage and heart attack (neither of which necessarily brought us any closer together I don't feel :/ ) but your opinion on whether this relationship is being over- invested by myself really. I had asked him what he thought about living together, but he explained his lifestyle was 'ideal' at the moment (he has a bachelor pad - a term he considers derogatory but I don't - with the whole Xbox, giant tv, adjacent workshop, etc) and he rarely sees me in the week, maybe to meet up for coffee, and always stays Saturday from about 8pm then goes back Sunday about 6pm.
We rarely phone eachother, just text. And today for instance, we'd arranged to go out somewhere together but it's afternoon now and I still haven't heard from him. If I text him I know he will reply with 'I was waiting to hear from you' but he's already complained he feels like a taxi driver, so my contacting him to ask we are ready to go, are you? Feels like I'm calling a cab..
Because we rarely see eachother, he doesn't seem to want to stay more than 1 or 2 nights at most, the problems he perceives with my son, the poor communication, that he's turned down the idea of living together, ... this relationship is petering out, isn't it? 
He's also been telling me lately about a teenager who has a crush on him through his work. He only mentions it in a bantery sort of way, but why? Is he trying to test my resolve or something?
He's a lovely man and I love him dearly, but this doesn't feel like a grown up relationship, it feels like dating in my Twenties. I suppose I've reached a point where I want to move things up a gear, but he doesn't, so how do I progress from here?