From urban dictionary:
To hinder, by whatever means, the chances of another male from getting a sexual encounter with a female.
Man, will you get da fuck outta here and stop cock blocking me you Ja Rule loving parasite.
Alright for guys this one is easy. It is a fucking cardinal sin to cock block one of your boys. Even if he is wasted off his ass and about to take home a Blue Whale, it is his choice as a man to go whaling, interference is heresy.
Although, I think cock blocking is permissible in one case. That case being if you also want to bang the chick he is going after and you actually have an equal or better shot.
For guys who have girl friends this gets tricky. Girls are cock blocks. They will either make it seem like they hate the other chick and not let you separate her from your cock blocking female friend, or they will just hang on you and not let you fuck anyway but make it clear to the girl you are actually trying to bone that she has no shot.
There is another common cock blocking scenario. The sober/ugly/jealous friend of your target. This person will either try to protect your prey by whisking her away from you, or will just stand in the conversation and fuck your game up the entire time. If she is ugly, she will talk about how hot she is and try to get you to vomit. If she is jealous she will act like she hates you and why would her other friend want to fuck a dude as douchey as you. And the worst one is the sober friend. She will guilt her companion about being a drunken slut, and at the same time bitch at you about trying to fuck a drunk girl and yadda yadda who cares she is sober.
The important part about cock blocking is knowing your cock block and the defense you can use.
Jealous Friend - Jealous friend just wants to be validated for being attractive like her friend you are trying to give the bone one to. This is a slippery slope. You must make jealous friend feel attractive and important (a good wing man is a perfect option) without actually going too far and making her ugly ass think you want to fuck her. There are some problems here, if the target is insecure she might get tricked into thinking you do want to fuck her friend. You must constantly assure her that is not true. A wing man is really essential for this type of cock block.
Ugly Friend - Ugly friend also wants to be acknowledged. But she is smart and will see through your compliments for the bullshit they are. This is when a special type of wing man is important to have around. The Grenade- Jumper. A grenade jumper is that friend everyone has who will fuck anything will a pulse either when wasted, or sober too. He will leap on the grenade and leave you home free. If none are around there are a few other approaches at your disposal.
1. The Tucker Max - Be a dick to her and see how long she can hang. Mix in touching and flirting with the insults to the hippo.
2. The Nice Guy - hey, nice guys get laid too people. Compliment both females and co-op ugly with alcohol. Ugly girls like to drink so they don't feel as bad. Keep a steady stream of alcohol pouring down her gullet and then separate her from target friend and smash.
Sober Friend - This is a fairly easy one. Sober people find drunk people obnoxious, use this to your advantage. Talk loud and make fun of sober friend. Ask her if she really believes that not drinking will earn her credits with some cloud-sitting deity who doesn't exist anyway. Ask her if her step-father got wasted and touched her so she hates demon rum. Be relentless. She is probably the DD for your target however, so this strategy will cost you cab fare. Who the fuck cares.
The bottom line is the guy who gets laid is the guy who has seen and worked through many cock blocking scenarios successfully. Practice makes perfect. There are certain situations where the cock block is not worth even fighting against. If the cock block is a blood relative of the target their bond cannot be broken except by the best of bullshitting or the fucking best wing man ever.
If the cock block is the target's boyfriend do not engage. Face-crushing may ensue, search for a better target.
If target is wearing a wedding band she may appear more attractive. However husbands do not react well to finding their wives in bed getting rammed in the ass like a prison shower by a twenty-something. In his bed. Do not engage target.
Also, in the event your friend cock blocks you and fucks the target, if you want to bitch a neutral friend must be called on to resolve the dispute. If both bro's chances of fucking the poon were even or in his favor, you must stop bitching. If not, he buys you a beer.
Stay thirsty my friends.