He’s 17 and a half and she’s 16. Been together about 6 months. He asked if she can stay tonight as they want to go somewhere together tomorrow. He’s my first born so feeling a bit unsure. I know they have sex and we’ve had a chat about respect and contraception. My mum never have let my boyfriend’s sleep in the same room as me even when I was at university and I remember it made me feel awkward, but obviously they’re younger than that.