Should I be worried or am I just paranoid??

So me and my boyfriend have been together for four and half years and we have a two year old, anyways I have met all of his friends except for one. Him and his supposedly guy friend are going to Boston for the day and I am staying behind taking care of our baby. Anyways I have done a reverse number look up on his friends number and everything that he has told me about him has added up right. Am I a tad bit jealous or am I just worried?? And he's never cheated on me before so I probably shouldn't worrie about it, but it drives me crazy because I have yet to meet this one guy friend