What fat and/or ugly girls do to guys who want to hook up with their cute girl friends.
Cockblocking is not nice. Fat girls do it because they can't get any so they get jealous and try to prevent other guys from giving the dick to their thinner, hotter girl friends. If you are a hot, horny girl and your ugly, fat friend tells you that that guy you want to bone is a player and/or has STD's, she's not really protecting you, she's just being a bitch-ass cockblocker cause she don't want you to get laid and be all happy. Cockblockers are messed like that