Weasley twins

The twins like to trail behind you through every corridor, like bodyguards. They don't let you near any boys, and any boy who dares to casually flirt with you ends up blue or turned into a toad. The twins were glued to you like glue until one day you went to "The Burrow" to visit your best friend Ginny, and Fred and George introduced you to Molly as...

Mother, she's our girlfriend...

The twins said it at the same time, in front of their entire family.