To not want so to stay over in London

[TooMuchJD]

DS & his gf are both 17 (18 in a few weeks). They want to go London and stay over for one night together. AIBU to want to say NO!! because I keep imagining scary scenarios where they're mugged/kidnapped etc. and don't feel they're very streetwise being from the sticks and "Up North".
They have been very sensible, got a nice hotel not too far from Oxford St, booked rail tickets, looked at closest tube stations etc. They are paying for it themselves with Xmas money.
He has stayed in London several times but always with family members.
Am I just being a tart about it

The OP has already agreed that he/she was being too over protective and was just worried. Job done.

OP, I hope they enjoy their mini-break!

I’d be more worried about becoming a grandmother than anything else!

Yes, far more likely.

I hope bloody not! They're actually good kids
Regardless. Good kids aged 17 in bed together. Erm ...

Oh Jesus. Get a grip.

The OP has calmed down which is reassuring. There is lots for a teenager to do in London.