Breakup Letter

Breakup letter admitting that you love someone else in a third party relationship.

I recently began seeing another [man / woman], someone that you don't know. I realised that I seem to have much more in common with [him / her] in terms of life vision that I can no longer pretend my love for [him / her] doesn't exist. Although I have not formally started my relationship with [him / her] yet, it's not fair to you for me to pretend our relationship is going to work when I know in my heart is somewhere else.