Are you Jealous
I love X, and I want them to be happy.
I may be sad at time, or slightly envious if they find happiness with others, but I am Happy that they are happy, and happy that they still want to spend time with me also.
Did you regret when Dad, would go drinking with his buddies. Sure you might have liked to have him at home, and some times you may even convince him to spend some more time with you, but you realized drink beer with his buddies made him happy, so you wanted him to do it some (as long as you still got time also)... For me relationships are the same way, I want X to be happy, and if thats with another person, I am happy for him (if sometimes envious), and I am even more happy, when he then wants to spend time with me...