He may have little tiny bits coming out during. This is called pre-***.

At the end his penis will become really erect and he will quite clearly be in a lot of orgasmic pleasure. Then he will *** a lot.

After that his penis will become more flaccid and eventually completely flaccid.

Keep going when he's cumming and once he's come keep going for a little bit more until his erection really starts to just flop.

He'll have a little bit of *** seeping through throughout the "toss off". The "big load" will come when he cums. You'll know when that is, he'll let you know when he's done if you cant figure it out.

generally you stop when he comes and it'll usually be all that the end. some boys come a little bit during but you'll know when hes finished. with my boyfriend though sometimes i just do it to stimulate him before sex and then he'll come during sex.

'tossing' off a boy? You mean when you're having sex, and you want him to get off of you, so you push him off? Well wouldn't you assume that you'd stop AFTER you both came?

Tossing off? I assume that is oral sex. General rule of thumb, stop when he tells you to stop.

when you choke on it, trust me you will know.