<human>: Could you distill the essence of the text into 1-3 sentences?

I have been engaged to my fiancé [25f] for two years.  We're in no hurry to get married, rather we've always been comfortable just being together.

While my fiancé (let's call her Susan) was away on business, I met a woman [25f] online (let's call her Kelly).  We spent two weeks almost inseparable, spending most of our waking time on the phone or skyping together.

Kelly and I are both interested in leading an alternative lifestyle, something Susan has not shown any real interest in.

I already feel more emotionally and sexually fulfilled spending time with Kelly than I do with Susan.  Kelly feels much more like a personality match for me than Susan does.  The problem is, I know I love Susan.  I know I could love Kelly, if I permitted myself to.  Kelly is in love with me. 

I have the choice between a comfortable, vanilla lifestyle with Susan, or an exciting, sexually fulfilling lifestyle with Kelly.  Am I crazy for even entertaining the thought of leaving my fiancé?
<bot>: I met someone online and she feels perfect for me.  Am I crazy for considering leaving my fiancé for the prospect of a new lifestyle?