Complex, indeed, Amanda...
Trying to imagine how I would have reacted 30-40 years ago (had BBM appeared then). I think my reaction would have been the same but for different reasons. I think I would have perceived Jack as "easy" "available" and maybe a little "needy." I'd have been attracted to Ennis for the opposite reason I am now, because of his stern, independent "masculine" demeanor... I doubt I'd have been able to see beneath it.
But today... hell, anybody under 45 is a "boy" to me... and anything under 30 is a "puppy" -- cute, yes... scratch 'em behind the ears and send 'em out to play.
Kudz