Ah no, if you are "teasing", stopping just when you know you are about to ejaculate, then what spurts gently out at that point is actually semen which has been released, but you have stopped before the ejaculation cycle is fully established. Not only that, but this semen likely contains a higher concentration of sperm as well, so a condom is absolutely critical from the start of proceedings; if this happens, you can see that "pulling out" at this point is quite useless in terms of contraception.
"Pre-come" is different, as I have explained above, is produced and comes out slowly and progressively as you continue with sexual excitement, but is much less likely to be seen when you are masturbating yourself without a the excitement of a girl up close. After all, that's why you want to have sex with a girl (even just a "hand job" or a "blow job" which certainly is safer than vaginal intercourse on many levels) - it clearly is more enjoyable than masturbating alone and your responses are different.
There are two forms of stretching exercise. The "two finger" method means simply that when you can get two fingers fully in the opening so that they pass through the opening and "hook" inside the foreskin, beside the glans, this allows you to hold the fingers apart to perform the stretch. I have not described anything different. Part of this method is that each extra finger you can fit in as well, allows you to hold the stretch with less effort by leaning the fingers against each other and "wedging" them in.
The second exercise, is stretching the frænulum by gripping the end of the foreskin where the frænulum starts, and stretching it fully away from the body - which means holding the whole penis on the stretch as the other end of the frænulum is attached to the glans just under the meatus or "pee hole". The rule is to do each of these stretches as often as you can, holding each for as long as you can - many minutes if possible. If you have the time, do one until your hands get tired, do the other (different grip) until that gets tired, do the first one again etc.