Is there some type of connection between Mavis and Zeref? In opening 10 of Fairy Tail at 1:15 we see Mavis and Zeref walking towards each other. When their lines of vision meet, a look of deja vu appears on their faces, indicating that they have meet before. Do they know each other and what is their connection? Did they once love each other? (That's the speculation on my part.)

Please watch the opening of Fairy Tail, Number 10 here first before answering my question so you have a better understanding on what I am asking in my question.

Answers are appreciated.
I think Zeref and Mavis had a thing. You know how Zeref said one day, that he realized the meaning of life and stopped all of his bad ways? Well, I think that day was the day Mavis died. Possibly killed by Zeref himself. He may have felt terrible and realized that he needed to be stopped. So as he awaits Natsu to get stronger, he stays near Mavis, enjoying her presences till the day comes.