QuestionI have many questions about myself. One is that I have a friend who is about 14. I am 13 and he just recently grew about 5 inches in two months. My first question is will he be growing much more if his dad is 5'6? Secondly, I can't help noticing that he has under arm hair, and when we take showers at school, I can't help comparing his penis to mine. His is not much larger than mine and he's older. Is that normal? Third we have masturbated together and his erect penis is 5.5 inches. Mine is 5.25 inches and I ejaculate semen. He ejaculates a clear liquid drop. I took the Tanner Stage Calculator for Boys and I did his. His Tanner stage of puberty is 4.2; mine is 3.4. Is it normal for me to be ejaculating more semen than him if he has a higher Tanner stage than I? I'm sorry this was so long, but I needed to get it off my chest.
I don't mind the number of questions you asked. I'm glad I can help you understand several things.
First of curiosity is quite normal. You are going through a lot of changes which you have never experienced before. Many of those changes are about private matters, which means few people talk about them and it isn't something you bring up in casual conversation. Thus, people naturally look for other sources to figure out if this is what supposed to be happening or not. Unfortunately, far too many people don't consider the quality of their sources. Comparing your development to someone else's only tells you about the differences. It doesn't tell you about what should or should not be. You'll find that boys near your own age are more willing to talk about these matters because they are experiencing the same changes and have similar questions, but they aren't experts because it is just as new to them as to you.
Just as every person looks different and some more different than others, the way humans grow is also different between individuals. I can explain general trends and give you rough ideas about what to expect, but I can't, for instance, say that in two months you will be 3 inches taller. The score of 3.4 from the Tanner Stage Calculator tells me you are on the verge of hitting your own growth spurt, but I can't tell you exactly when you will see it.
Will he grow taller?
You told me how much he has gained, but not how tall he is, so I have not clue whether he will end up taller than his dad or not. I can tell you how to guess. There is a Adult Height calculator on this site as well. There are two calculators on the same page. The first makes a rough guess mostly based on a person's DNA. It is known that if you take the average of your mom and dad's heights, then a boy's height will average five inches about his parent's average height. The problem is that the accuracy of this estimate is poor, it can be off by as much as five inches in either direction.
The second calculator attempts to narrow the range down by factoring a person's age (as a rough guess to their Tanner Stage) and their height and weight (a rough guess as to how well they are eating). This one is within an inch and a half of your final height most of the time.
But by the Tanner Stage of 4.2 I can tell you that he is still growing, but not as fast as he has been recently. Most boys will gain about 2 to 3 inches while they are in stage 4.
Why isn't his penis bigger?
Like other features on the human body, the size of a person's penis varies. Actually the flaccid (not erect) state of a penis varies in size constantly for a number of reasons. If you are hot, the penis tends to get longer to give more surface area to the skin and thus get rid of extra heat. If you are cold, it shrinks to reduce the amount of heat loss. If you are even slightly sexually aroused, your penis gets larger. If you are active, it tends to get smaller as the blood in your body is called for in your muscles. But as you noticed, when you become erect, the differences in size becomes less noticeable.
The average adult penis is about six and half inches in length when erect, but that is just the average. Typical size (what covers most of the adult population) ranges from three inches up to eight or more inches. There is no way to predict the actual size of a man's penis when he is grown. People have tried but nothing has worked with any accuracy. From your description, you will likely end up with a slightly bigger penis than he when you both reach adulthood. But it won't make any difference; just as he might end up with bigger feet than you. Size doesn't determine who is "better." And when it comes to the day that you marry and have sex, size doesn't matter in regards to sexual enjoyment for the husband or the wife. It is how sex is done and not the size of your equipment that makes the difference in enjoyment.
Why can I ejaculate semen and he can't?
Ejaculating semen requires several independent systems inside your body to both mature and work together. For boys, most often the systems come together in stage 4 and that is when ejaculation starts. However, for some boys the systems come together sooner, in stage 2. I suspect it is about half and half, but I haven't found any studies yet to verify this. My guess is based on knowing that girls have a similar event -- monthly blood flows -- which can start either in stage 2 or stage 4 and it is about half and half for them. I assume it is similar in boys with ejaculating semen.
Thus you are in the group that starts in stage 2 and your friend is in the group that starts in stage 4. The clear fluid that is coming from your friend's penis is pre-ejaculate fluid (commonly called pre-cum in slang). It is produced by the Cowper's glands to clear out your penis prior to ejaculation. It is also a lubricating fluid for sexual intercourse. You will eventually produce this fluid as well, but I suspect your Cowper's glands aren't as mature as his are at the moment. But then your seminal vesicles, which produce the semen, are more mature at the moment than his are.
But while we are on this subject, we need to talk about another matter. It isn't proper for you to be masturbating with other people. Your genitals and the things that go along with them are supposed to be private. "No, much rather, those members of the body which seem to be weaker are necessary. Those parts of the body which we think to be less honorable, on those we bestow more abundant honor; and our unpresentable parts have more abundant propriety; whereas our presentable parts have no such need. But God composed the body together, giving more abundant honor to the inferior part, that there should be no division in the body, but that the members should have the same care for one another" (I Corinthians 12:22-25). Your genitals is the weakest part of your body. If you ever have gotten hit in that area you know why. To balance that, we treat that area of the body with greater modesty by keeping it covered. Thus it has greater honor, something that you then only share one day with your wife.
Now circumstances will cause people to be seen naked at times, such as in school showers, but we tend to limit those times. But the sharing of very personal things, such as ejaculating, is to be limited to your future wife. I know curiosity makes boys want to know whether another guy's equipment works the same as his own, but the fact is that what you two did wasn't modest.