Merging 2 families - worries, concerns, plans etc

[GuitarDadOf2]

I thought I'd do a name change and pu this one out there as it's something very much on my mind, and I'm betting that many of you folk have either been through it or have thoughts to offer...

In short, the subject of me moving in with my girlfriend has come up more than once and it's something I'm seriously considering. She has a 6yo DD and I have slightly older DSs (one teenage one somewhere in the middle)

In terms of feeling as though I want to live with them, I'm fine, it's the merging the families bit and how it'll affect my boys or how they may react that weighs on my mind - haven't discussed it with them as yet.

Background:
I split from my ex nearly 2y ago (after many years of mutually 'dead' marriage - which we ended extremely amicably, children share time between us on a routine but mutually flexible basis - ends up being about 2/3 with her and 1/3 with me averaged over the course of any given month) I was single for about a year, and have been with my GF for a bit less than a year (note to self - must be coming up on that - check!)

She's spent most of her DD 6 years on her own so they are very much used to their home being theirs - so there'd be bound to be a big impact on her DD with such a huge change to their lives.

My DSs are very different - the youngest is emotionally bombproof and very open, he'd love it I think, the eldest is classic teen - going through the uncommunicative phase and has generally been a bit more emotionally closed - I worry about how we'll react to it all - he's generally been a bit more guarded around my GF on the occasions when they've been together (dog walks, meals out, that kind of thing)

There are loads of clunky practical considerations that whizz around our heads (doubling up furniture - do you sell or store - does storing say 'this might not work' ? , need to tart up the spare rooms in her house, space for me to work from home (50% of the time is the norm) and all that - but it's the people stuff that's most on my mind.

So before I start imagining all the possible problems, be interested to hear other people's experiences (both positive and less so - there's things to be learned from both I think)

thanks in advance for any comments

@thecatneuterer I want to live with my boyfriend because we love each other and weekends together just don't feel enough for us.

I waited 3 years before combining dp (childless) with me and DC in one household.

It's worked out well but we took it really really slowly and make everything easily reversible that makes sense. We rent together. We have not got rid of any furniture. We have been clear with one another that the DC comes first and if there is any discord that affects DC, we will be separating households.

The way you talk, it sounds like you dont like to suggest to your dp that things may not work etc? Is there a reason for that? Because ime its essential to make allowances for the relationship/blending of families to fail. If you dont do that, you become more likely to stubbornly push through difficulties that need to be handled more sensitively etc.

My dp loves my DC, after knowing them 3 years they now say "i love you" to him etc and seek him out. Smallest one is your dps dds age and he reaches for dp hand in public, seeks help and comfort from dp, etc. If I'd thrown them together too early, that natural attachment would not have formed and we will have been in discord imo. Children need time to form deep and trusting relationships with others. While you can go quickly, they can't and need to be handled with compassion and patience.

Our timeline was - met dp late 2015, dc met dp in early 2017 (youngest was 4), we moved in early 2019 (youngest was 6).

I think you should slow things down and allow natural attachments to form via shared activities. Including mundane activities like homework, picking up from school, cooking together. Not just hols and days out iyswim.