Time to Write: 6th July

Once again Rachel Poli invites us to participate in her Time to Write Challenge
https://rachelpoli.com/2018/07/06/time-to-write-sentence-starter-36-creative-writing-prompt/

‘Who invited him?’ she hissed.
‘I have no idea. I don’t even recognise him. Do you?’
‘No. I don’t.’
The party was in full swing and the object of their attention was leaning nonchalantly against the back wall, the disco lights dancing across his features.
He wasn’t much older than they, but he seemed content to watch from a distance rather than approach anyone or join in.
‘How are you enjoying your party girls?’ their mother asked as she swished by in a froth of pink tulle. ‘Fancy dress was such a good idea don’t you think?’ She giggled and did a twirl.
Grabbing her arm, Chloe  asked her who the young man was leaning against the wall.
‘Oh wonderful! He came!’ she gushed and waddled towards him like a duck souffle.
The two girls stared at each other.
‘She knows him?????’
‘She’s bringing him over!!!!’
‘Girls, this is Terry. Terry, these are the birthday girls, my daughters.’
‘Er, hi.’ Chloe and Chris said in unison.
Close up he was older than they thought and a horrible idea began to manifest itself.
Looking sideways at their mother, Terry said
‘They don’t know, do they.’

Note:
I’ll leave it to the reader to decide who ‘Terry’ is.