After having a song written for you, you'd think a last thing any guy would want to do is start dating the person who wrote the song again, but if recent rumors are to be believed, that's just what John Mayer is doing. According to new reports, Taylor Swift and John Mayer are rumored to be dating once again after Mayer’s recent split with Katy Perry. Well I guess Taylor does have a new album she's writing music for so anything is possible.