It would be a completely different situation if they actually knew the poor man. They don't. The E's have seen him maybe a few times in their lives, but they don't remember him. They barely know Grandma, and Jonathan can't even remember if the kids have ever been to Scotland or not!
This is all for the vlog, and for him to score points with his audience. His poor mum started the conversation saying "Well, it's not going to work Jonathan, because he's just.. he's just... laid down and just exhausted unfortunately.. so... um... sorry about that. " Does that sound like someone who wants the whole SacconeJoly gang to bulldozer into her house while she is trying to say goodbye to her partner of 20-odd years??
But he was already filming, the kids were right there, and he had already rented the camper van, so she couldn't say no...