DO I HAVE THE RIGHT?

jakie
So the other day we went skiing with my boyfriend(we've been keeping it private though)and his friends.He cane over to pick me up from my apartment and normally I headed straight to the front seat but he showed me to the back seat apparently he had a lady friend who is a colleague seating on the front seat.I couldn't beleive it.I am not the jealous type but at that moment I felt really upset and I wish he'd consulted with me earlier.It changed my mood for the whole day nad I felt like I needed to just quit hoing but I did.They didn't seem intimate but they would spend most of the time together.Do i have the right to feel jealous or am I overreacting?