Don't know about CX, but on SQ, you will be asked to go back to the cabin they are travelling in and do your tucking in there.

Sometimes the CSD may allow a short visit but in all honesty, they may just suggest you go to their cabin instead of them coming in.

Yes I agree with everyone else here. If you want visitors, sit at the back. Not in front. Your children may sit for a while. But cannot whine. Nor can they sit with you during meals.

The cabin crew may allow it but you will be at the bane of your fellow passengers.

Just my take.