Would you let your 2yo go to a neighbours?

[littleboyblue]

We live in a first floor flat and the other day, my neighbour who lives downstairs asked if my ds could go and play with her ds (who is a few years older).
I said yes, but don't really know them. We have lived here for a year and always stop to chat to this family who seem very nice. She is a school teacher, her dh is a bus driver (I think) and their ds is lovely. They are religious (not sure why I'm mentioning that) and I'm sure ds will be fine, after all it is only downstairs and I'll be in my flat with ds2 so am on hand if anything happens.
Just thinking, should I let him go? Am I being too PFB if I don't?

I would go as well, at least the first time and not leave him there until I felt comfortable with it, whoever the people are.

That's what I thought. If I'd invited her boy here, I'd have asked her to come too for the first time.
So do I just say to her that I want to come? Or should I let ds go and then 10 minutes later take something that he must have with him and stay?

I would just take him and say - I'll just hang around a bit to make sure he is settled and then I'll nip back upstairs - bring him back if he gets upset.

And agree to go back and get him in maybe 1.5 hours (any longer and he may be getting overtired).

That's a good idea. She said she'd come get him, but I'll tell her that he's just snacking and I'll bring him down in a min and then hang about for a bit and then collect him after an hour and if it goes well, she can have him as often as she likes