Just that really. He's been with his girlfriend 3 months, he's 17 (18 in may) she was 18 last month.
She's comes over 4-5 times a week and sometimes stays in a Saturday night.
They sit in his room and watch tv.
I'm in bed next door to ds. I thought I heard the bed quietly banging, then dh messaged me from downstairs saying he'd just heard them having sex, he heard the bed. Obviously he's not happy about it and neither am I.
I've just texted ds didn't want to go in and told him what we heard. He's denied it.
What would you do?