My friend went to live in another country and he’s back to celebrate Christmas with his parents

So, basically, my friend Simon and his two other siblings went back to our home country and now they’re back. They went to my house to celebrate Christmas because we invited them and its so awkward because I don’t know how to socialize with him because we barely talked when he was in our home country. And now that he’s here I don’t know how to talk to him and I can’t just act like I talked to him all the time when he was away its gonna be so awkward 😭