Lady LIB readers: Should I be worried? My BFF is urging me to date her ex

From a female LIB reader

My best friend dated this guy when they were in school and they broke up after he cheated on her with a certain girl. Now I met this her ex recently and he is professing love for me. I called my friend and told her and she goes "You better say yes. I want to be a chief bridesmaid". She's been forcing me to call him and all. Although I like the guy because he is made and actually my spec but again he is my best friends ex-boyfriend. They dated for three years. The weird thing in all of this is her seeming 100% support to the proposed relationship. Should I take her for her word or be scared?