He believes he shouldn't be in love with you. It was forbidden for a high preist to fall in love, it was seen as sinful, he was ment to be the picture of purity and all the was holy.

"Please.." he let out a soft breath, he couldn't bear the pain you were feeling "My darling dove..forgive me for all that I have...I can no longer torture myself from my duties and loving you at the same time" his voice was soft as he spoke to you pleading for you to no longer love him