Advise please....I reside with my Significant Other (SO) about 1-1/2 years now and ....?

No obligation on his part whatsoever.

Go and have a great time.

You can't make him go, but you can observe and make a mental note for the future. If you have certain expectations, you need to communicate them clearly. Your question is a contradiction - you say it doesn't bother you that he won't go, and yet in the same breath you're asking if you should "insist" that he goes? The most important thing is not the exact way you handle your family trips, but whether or not your and his needs are being met. My husband and I are in agreement that it's important for us to visit our families together; what you and your significant other agree upon is up to the two of you. But you do have to agree on something. Don't just pretend that it "doesn't bother you" that he doesn't want to hang out with your family, while the whole time it's eating at you and is causing disappointment.

I find that when I have to insist, things don't turn out so well. Your SO should have the freedom to choose, although if he loves you you'd think he want to go and make this into a kind of getaway for the two of you. (My husband and I have tons of fun on flights and while waiting in airports!)

If he does decide to go with you, it would be a nice gesture if you did cover the cost of his air fare. After all, he wouldn't be going at all if you're weren't.

if "He is not interested in attending" and it doesn't bother you that he doesn't want to go, then why would you insist that he do go?

He obviously doesn't want to go because he doesn't love you and hates your family.

There, you give me a rude answer and I'll give you one right back

Go by yourself. You will enjoy it more than if you force him to go and he is a putz

go and have fun with your family!