My DS is in yr8 highschool. Last year this happened a few times but since they restarted its been every day.
His friend is a nice kid but his mum drops him off outside my house at 7.30. I don't know her, never spoken to her.
At 7.30 we are just getting out of bed.
A few mornings I've told my son to tell him to come back at 8am if he wants to walk to school with him but he came back 10/minutes later.
This morning I let him in because there was a rainstorm.
And now he's back. Walked home from school with DS and asked if he could come in. I reluctantly said OK and then he asks if he can stay till 5pm 
He has done this previously and asked if we 'have any food'.
I know it's not MY responsibility but i feel bad that this poor kid is being booted out at 7.30am till 5 on school days rain or shine.
But I don't want him here tbh. I've 4 kids of my own.
I know you're gonna say grow a backbone but I'm terribly british about these things and have bad anxiety and am crap at confrontation. Plus...the guilt! :(