Katy Perry, 35, And John Mayer, 42—7 year difference

We’re not actually sure why we’ve included these two, because the 7-year difference between them is the least notable thing about their relationship. Indeed, their relationship was on and off all throughout, and more than a few break-up songs were even written about it. In the one and half year of their relationship, the pair had split for three times. Also, there were rumors about their engagement for several times.

The actual details of what happened were never given, but, to be sure, they did dominate the tabloids for a while, and were often photographed being handsy with each other in public. They even released a duet song about falling in love, which managed some degree of success. But, alas, it was love lost. They ultimately ended their love story in 2014. After all, the songs that they wrote to each other during this period were gifts to all the audience.