The Sun is always facinated by the going ons in the Royal household, and they shine their puns on Prince Harry's and Meghan Markle's relationship with the headline "Has Harry Pupped the Question"?  The speculation as to whether he had asked her to marry him arose amid reports that the US actress has moved her dogs to the UK - hence the "pupped", instead of "popped".  

In English, if you "pop the question", you ask someone to marry you.  A puppy (or pup) is a young dog.

More Marriage vocabulary.