I am sorry, but I need to be blunt also - The simple answer is "Because alcoholics lie." Even if it is something as sacred as saying "I love you." Who she is will be dictated by her actions, not her words. Even "she is planning on dumping him soon" may be a lie.
Being lied to is painful, and for those of us that try to lead lives with integrity, it is often difficult to accept the levels of deceipt that we experience with active alcoholics.
Off topic - Just a guess here - but "Go Hokies?!?" (If I am way off, then ignore)