It's like going on a trip with boy friends family and not being invited, old high/college school trips and not being invited.  What it comes down to is your relation ship with this clod just a friendship or after almost a year are you both serious, if your not living with him or just a house mate, going steady, engaged, betrothed or any serious commitment, then your just a friend and he's right not to take you with him, he probably dosn't take his other new friends either.  How would you feel if you and your girl friends wanted to take a trip and he insisted he go along.  It's a whole different thing if you are in a serious committed relationship with an outcome that can lead to kids, marriage or permanent companionship, then you should be with him and he with you everywhere.    Now you have to ask yourself what is your relationship with a boy or girl friend.  If there is no relationship, then maybe its time for you to maintain your friendship, but move on.  A-MEN