According to Us Weekly, Katy gave the musician V.I.P. treatment during the Capital FM Summertime Ball in London on Saturday.
"Katy made sure Rob could roam around freely backstage and do as he pleased. She also gave him a list for five guests to attend," a source told Us. "Rob was in the pit with his friends for her set but was singing the wrong words! It was quite funny but very sweet."
“Katy made a real fuss over him and made sure he was well looked after,” another source added.
While insiders have claimed the relationship “wasn’t that serious, it seems to us like these two just can’t stay away!