text: Spain's King Felipe and Queen Letizia put on a united front today, as they stepped out for the first time since explosive new claims about the 47-year-old monarch's father emerged. According to a new book by a former royal correspondent, the former King Juan Carlos II had a long-running affair with a German socialite during the final decade of his reign. But if Felipe and Letizia were upset about the revelations, they certainly weren't showing it as they arrived at the University of Alcala de Henares to present the Cervantes Prize for Literature. Scroll down for video . Claims: King Felipe and Queen Letizia present a united front following the latest Spanish royal scandal . Walking arm-in-arm with his 42-year-old wife, King Felipe, who took the Spanish throne last June, kept a straight face as he approached photographers. Later, as a group of ukulele-wielding students appeared to serenade the royal couple, Felipe even managed a small smile. Well-hidden though any private anguish may have been, the news will have undoubtedly come as a blow to the Spanish royal who has been attempting to overhaul the image of the monarchy in Spain since taking the throne. His father Juan-Carlos was famous for his love of freebies, even, on one occasion, accepting a yacht called Fortuna as a gift. Not good: A new book by journalist Ana Romero (left) says King Juan-Carlos had a decade-long affair . Divorce: It also claimed that Juan-Carlos contemplated divorcing Felipe's mother, Queen Sofia . Unruffled: The Spanish royal couple kept any worries about the allegations under wraps during the visit . Light relief: Felipe managed a small smile while being serenaded by a group of student musicians . In June 2012, with the Spanish economy in crisis and unemployment running at close to 50 per cent among the young, Juan-Carlos was photographed enjoying a lavish hunting safari in Botswana. The trip, which was not announced in advance, only became known to Spanish taxpayers when the 77-year-old was injured and had to charter a special plane in order to get home. Juan-Carlos' African jaunt, a freebie paid for by Syrian businessman Mohamed Eyad Kayali, led to widespread calls for his abdication, which he did less than a year later. Since taking the Spanish throne, Felipe has introduced a new code of conduct  which  bans royals from accepting lavish gifts and also outlaws private business activity - the latter in response to a fraud scandal that  enmeshed his sister Infanta Cristina in 2010. He has also included a stipulation that insists members of the Spanish royal family behave at all times in ways likely to 'please' and 'earn them the gratitude of'  the public. Blow: The  scandal is a set-back for Felipe who has been trying to change public perception of the monarchy . Freebies: Felipe's new rules include banning all royals, among them wife Letizia, from taking freebies . Behaviour: Royals are expected to behave in a way that earns them the gratitude of the Spanish public . Despite Felipe's best efforts, his father's legacy remains troublesome - in particular his record of extramarital affairs. Most recently, a Belgian woman named Ingrid Sartiau filed a paternity suit against him - a case only made possible because of his abdication. Juan-Carlos is also believed to have a second illegitimate son, Alberto Sola who was born in 1956 and lives in Barcelona. The latest scandal focuses on the final decade of his reign with Corinna zu Sayn-Wittgenstein, a German 28 years his junior, claiming to have had a lengthy affair with the royal. Speaking to Ana Romero, a former royal correspondent and the author of a new book called Final De Partida [End Game], Ms Sayn-Wittgenstein claimed that Juan-Carlos had contemplated divorcing his wife Queen Sofia in order to marry her.
target: King Felipe was making his first appearance since the claims emerged .
  New book alleges his father had a 10-year affair with a German socialite .
  Corinna zu Sayn-Wittgenstein claims Juan-Carlos wanted to marry her .
  Felipe, 47, was joined by  wife Letizia, 42, at University of Alcala de Henares .