Two characters are having a conversation. Instead of facing each other, they both face the camera.
No pregnancy is ever planned.
If you are having an affair with your partner's father/brother/son/best friend, you still don't use contraception.
If you are having a secret relationship, you snog in the middle of the village/square/street in broad daylight.
If one character wants to hug another, instead of just hugging them, they say 'Come here', so the huggee goes to the hugger to be hugged. Do people really say this? Is it a Northern thing or just a soap thing? (They do it in Emmerdale and Corrie.)
Especially in Hollyoaks, young women with no visible source of income always have lots of new, fashionable clothes.
Long-lost, or previously unknown, relatives always arrive to stay indefinitely without first phoning, writing, texting or emailing to ask if it's OK.