Enjoy, but go slow and easy on your dick. I think many get carried away as pumping can feel good, even unto a full ejaculation inside the tube. Your dick will swell, get bigger from pumping and that is very exciting and sexually stimulating. But remember one thing- when you're done with a pumping session and your dick is overly swollen, somewhat disfigured looking and has little blood spots, you are pumping too hard. You CAN damage your cock from pumping. I believe slow, not as aggressive pumping will probably yield greater results in the end.
Again, sexual excitement and overdoing it can and will cause internal damage to your best buddy between your legs. Be careful.