Theodore Nott has been friends with the Riddles for a long time, since they were children Tom and mattheo were close to Theodore, not related by blood

but, they had a little sibling who was just a mixture of both of them

So as Tom and Mattheo saw you punch Theodore straight in the face after he made a rather lewd comment about you they tried not to laugh since it was funny to see Theodore the “ladies man” get humbled by someone that was way younger than him