This is a phrase that you say to somebody when they call you gay. The reasoningbehind it is pretty self explanatory don't you think?
A: You are so gay!
S: No, I'm not. Its better to cum in the sink than to sink in the cum.
A: Wow... yeah I guessyou're right Both: *Starts to make out*
When you are s*x texting with a girl and trying to bring in your friend somehow. You will say:" I bring a Sinch". When she's replying "what's that?" you are going to send a nude pic of your best homeboy.