Your girlfriends may be like you
I am sure you have a few girlfriends. If you do, those girlfriends probably share some of your interests, or your personality.
So, if you bring your guy around these other women, you should definitely watch how he reacts and treats them. If your man is attracted to you (because you are stunning, fun, and wonderful) then likely he could find your girlfriends likewise enjoyable to be around and he may even be physically attracted to them.
Don't become jealous
Keep your cool, because your friends should ultimately become friends with him as well.
It is important to understand that although your boyfriend may find these girls appealing, he doesn't overly shower them with attention or seem to be flirting, out of respect for you. If you find him doing this, or if he ever were to come on to one of them, then it is important that you first confront him and second be very diligent to make sure that he is true to you.
Remember that throughout your entire life, both of you will find other people attractive and appealing. A mature relationship understands this, but both people are careful to still make the other partner feel most important.