shagging or absent and babysitting...? (WWYD)

[LoopyLoopsOlympicHoops]

Just went to the neighbour's house to pick up DD (3) from our friend's house, who took her and their DD (6) to soft play this morning (am abroad, is afternoon here). Their DD opened the door. Both girls curled up on sofa. No adults anywhere to be seen. Main bedroom door open, no noise...? I imagine they are in bed. Their room next to living room. Just popped back to consult with DH.

Should I

a) announce loudly that I am there, where are you...? And raise them if there, if not take DDs here

b) Just take the girls, leave a note

c) take my DD, leave theirs

?

Is this some sort of parallel universe?

Is it possible that they didn´t hear you or were outside?

I certainly wouldn´t assume that I needed to take their daughter as well as my own.

I´d have looked for them if there was no reply.

Certainly not left 2 young children in a place where I was thinking that they might be alone!

I can´t make any sense of what you did at all tbh.

No, no garden, bedroom right their, door ajar. They only way they couldn't hear is if they were in the ensuite or fast asleep (or deaf? But they aren't)

It does sound a bit odd, made perhaps more normal by the fact that they are right next door, perhaps