Hatred arising after a friend tried to make my fiancé cheat on me
The issue is mostly between you &amp; your fiancé (rather than the guy) since it is your fiancé that must establish appropriate boundaries with the guy. If he is to remain your friend, naturally he should apologise to both of you. If he remains your friend, you must communicate your personal concerns directly to him (rather than hold them within you). 

However, Buddhism does not state you must remain his friend because Buddhism warns against 'false friends' &amp; 'bad companionship', particularly those who are womanizers &amp; alcoholics. 


  12. "These are the six dangers inherent in bad companionship: any rogue, drunkard, addict, cheat, swindler, or thug becomes a friend and
  colleague.
  
  15. "Young man, be aware of these four enemies disguised as friends: the taker, the talker, the flatterer, and the reckless companion.
  
  http://www.accesstoinsight.org/tipitaka/dn/dn.31.0.ksw0.html