When I married my DH I already had a 4 bed flat in central London, he moved in with me and that's where we live together now, along with our 2 year old daughter and 5mo old daughter.
I don't really enjoy having people staying round because i like having my own space, we are already a family of 2 kids, 2 adults living there... but equally it's a 1.5hr drive to my in laws' house, they're in their early 70s and keen to spend time with their granddaughters so I've offered them if they want to stay overnight on the weekend they visit (they come once a month or once every two months).
My fear is that they will start to use our place as a place to crash, and as I say, I'm ok with guests staying as an exception but dont want the spare room to be up for grabs every time they fancy a night in London. At the start of our marriage they dropped a few suggestions like 'we're going to the theatre in London in the evening, can we stay over at yours?' and 'I'm meeting Friend A in central London so maybe I can stay over at yours?' That felt like an invasion of privacy (inviting themselves) and for that reason they haven't been invited to stay for these 3 years.
If they truly need somewhere to stay on the regular they can get a hotel (they won't because wouldn't want to spend on it, and they'd instead drive back same day). Staying with us is for occasions when they're meeting us, we've invited them and the drive back doesn't work well with timings of when we are meeting or when it gets too dark to drive etc.
How do I prevent this happening again whilst trying to be accommodating to their age and length of the drive?