Christian Horner is under investigation after he was accused of inappropriate behaviour. The Red Bull Formula One team boss – who has been married to pop star Geri Horner since 2015 – is the subject of an ongoing investigation by the motorsport team, which has confirmed that it’s taking the allegations “extremely seriously”. In a statement, Red Bull said: “After being made aware of certain recent allegations, the company launched an independent investigation. “This process, which is already under way, is being carried out by an external specialist barrister. The company takes these matters ext…