Brown_Eyes::::
If you know what he tastes like, that makes it a lot easier.
If you don't, let him cum in your hand or on a tissue or something and taste it. The taste will be stronger if he cums in your mouth, but it's relatively the same. It will most likely taste something a little like the smell of bleach and something sweet at the same time.
If you like it, and you're not averse to giving headjobs, just pull back until just his head is in your mouth when he cums. If you're giving a handjob, just cover his head with your lips and suck on it a little so you make enough suction to keep it from running all over the place!
