<human>: Can you condense the text into three sentences or less?

Guy (17) here, I've been with my girl for almost 8 months now and she is 16.
So we've been through a lot, it's both of ours first I would say somewhat serious relationships. For a while now, her mom is involved in everything related to us. She is divorced and doesn't have a companion herself, but she wants to know ALWAYS where we are, what we are doing, and what's been bothering me is that she limits mine and my girlfriends time together. Her mom has her for a week and then her dad gets her for a week. But say this weekend, I asked if we could make plans for Saturday, and she said no because her mom wants to spend time with her, and so today, Sunday, I ask when I'm coming over, and she answers that I have to come at 1 and leave at 5 because her mom wants to spend time with her. 

This limitation pretty much ruins everything because she goes to her dad's at 9. Why does her mom so badly wants to limit all of our time together even though she gets 10 times more time with her than I do? I'm pretty much fed up with it, I mean I know we are teens, but I am going to be 18 soon and I have a fulltime job, I'm already in college and I'll be moving out in the summer so I am independent. For example in my case, my mom never wants to spend time with me and she never limits my time with her. What do I do? Should I end it or hope for it to change or introduce change? Am I in the wrong?
<bot>: When a parent is limiting the time me and my girlfriend spend together... is that normal and what can I do about it?