First of all, because he has been unfaithful to you,

I don't get it, if it meant nothing to him, why he would jeopardize the relationship by telling her?

I say "hit the road, Jack." What good will a "lovely" home and cute dog be to you if you are miserable and living with an unfaithful man? (who by the way, doesn't even have the decency to marry you after five years of dating, but expects you to commit to living with him?!?

Buying a house together is a big commitment.

He is basically playing marriage without having to commit to it...)  This will plague your relationship, and the fact that you are questioning your feelings for him is only more proof that He must not be the man you thought he was.

Second, why would he have a reason to be faithful to you if cheating is so easy? If a few kind words and deeds is all it takes to win your allegiance again, then what's to deter him from doing it again?

So... what would deter him? A good punishment?

Do not be fooled by loving words and a remorseful attitude -- talk is cheap!! And if sex is so casual for him that he would jeopardize a serious five year relationship for a "quickie over a desk at work," how could you ever trust him? You deserve better!  In fact, everyone deserves better than that!

My advice to you is DON'T SETTLE FOR SECOND BEST. Realize that you were created by a loving God who has a wonderful plan for your life. If you give your life to God, He will take care of you and provide for you. Allow Him to be your comfort and strength as you step out and stand up for yourself!