Dunst's Regan, Caplan's Lizzy, and Fisher's Katie (best friends around 30) are saddled between sobering drama and physical humor as Headland's script doesn't adjust enough for a reality check or enough sympathy for them as they happen to cater to overweight Becky (Rebel Wilson) whom they used to call "pig face" back in high school. Wilson might have been able to show off more of a witty side had the writing not been devoted to the malicious intent of wounded singletons like imperious Regan, pepper-mouthed Gena, and drug-addled Katie. Becky's dress is 'marked' up a bit as the lascivious, calculatingly, narcissistic 'ladies' have to go through a lot and deal with issues in getting back at the woman who's beating them on the fast track to happiness.
A 'bridezilla' tale turns out to have less shock value and unpredictability than what was intended and more in the way of disbelief though it seems to have an honest, raw bitchy ardor going for it in the earlygoing that has some acerbic line-readings (one wonders what Diablo Cody could have done with the material if Headland let her have her way). The male actors like Adam Scott and James Marsden obviously play second fiddle in what may be consider artistic in an oddly absinthian way when one considers pleasuring, as well as bulimia and overdosing intrinsic to how relationships turn out. Bachelorette could have been a more potent reinterpretation of Bridesmaids using the 'On Demand' format to its advantage, but its cruel, gratuitous machinations render it a mediocre, enervating escapade to more zestfully naughty entries in the genre over the past generation.