Originally Posted by KyleKat
Why is it impossible for him to be supportive of her current relationship status and also want to date her? Clearly she's not exclusive, so his interest in her isn't taboo.
Because he said he is completely monogamous, so it is fair to presume that if he is interested in dating her, he is either a) not serious about being monogamous? or b) wants her to split up from her quad.