Departing should not have to be troublesome, you have to go home eventually. If you have to cut your time out short, let everyone know why you have to leave if you are okay with sharing it. If not, you can explain you have something personal to take care of before the day ends, or you have something to do with your family. The key is to sound believable so that no one will question you being bored and wanting to go home, or something along those lines.