Traveling without your partner for the first time brings up an interesting predicament in a relationship. The significant other may expect to be invited or to tag along but the reality of traveling without your partner is that it is healthy to get some time off from each other every now and again. A nice bonding trip with your friends can be equally beneficial for both parties. The one going on the trip gets to enjoy some time with their closest friends and it gives the other an opportunity to spend some time with their family or some of their friends.
The trust issue is a completely different factor. If you feel as if you cannot trust your significant other when he/she decides to leave for a weekend getaway without you, then your relationship probably has some bigger issues than dealing with spending a weekend apart. I don’t mean to sound like a broken record because Marckens brought up this point in his post but trust ultimately defines how healthy a relationship is. There has to be a certain level of respect between both parties within the relationship which includes being able to know that either one of you can leave for a weekend or really for as long as the trip lasts and that person will act in a responsible manner.