Men are Men and they need "guy time" just like we need girl time. With that being said, I would never go where I'm not invited...I'm way too proud for that. I would never sneak over and spy on him either - that is just asking for pain and misery - don't make yourself vulnerable. If I was the OP - I'd make plans for myself and follow through on them. Sometimes that's hard to do...with a bruised ego and a broken heart - but it's important to be comfortable with yourself when you're on your own. Don't be insecure about him don't be jealous of his alone time. Be confident. Be strong. Be good to yourself.