Ok, take a look at this pleace:
From Google:
Blow: a powerful stroke with the fist or a weapon; "a blow on the head"
Now, this word has other acception, like the ones that you imagine before, but the use that i wanted to give to it was this one.
we should make a note for the members that stays too long in the forum, because they start to talk like 
The note have to pop up every 30 mins, and says: "Go outside, meet a girl! feel the air!" this will be very useful for many of you! 
first of all... i come to the forum when i cant do anything else... for example, when i work this 9-5 mon-fri office job... you might say, f**k the job... go get a girlfriend... im auright... i get payed f**k loads of money and get to shag randoms on weekends... lets not forget, its only a temp job... till a month and abit when ill be completeling my gap year by travelling india and southeast asia for 6 months... dont get me wrong, awesome forum, definately serves its purpose, but my priorities are spot on at the moment...
now... regarding the word "blow"... yes... it has other meanings, as do most offensive words... like cock, ass, pussy, f4ggot, f4g, g4y, doosche, oh man i could go on... the point is... its the context... see this quote below?
If this were in spanish, i would have blow you, but as it is in english, i will let you go on.... for now 
It definately implied you wanna give him head...
Oh SpinStorm... it's weird i always got the impression you were the kinda guy who collected his piss in bottles...
