Shady boyfriend

So I’ve been dating this guy for over 4 months now, i feel like he’s just a little bit secretive, we broke up for like a week before but we’ve been back together for a while but he still hasn’t told his parents that we’re back together, i have not clue why because they love me and never had a problem with me, they can tell that we’re back together but he won’t admit it to them, so that’s weird to me but also he never involves me with anything, i asked him if he wanted to hang out tonight but he said “I actually have a party to go to at the time” but he always says things like that, it just makes me think “why doesn’t he ever invite me or ask if i can come too?🧐” all of our friends know we’re dating so I don’t think he’s trying to keep that a secret or something, I don’t think he talks to other girls but i also kinda feel like a side chick, it feels like he’s cheating but there’s no other girl, it’s weird.