Can I spend less time with my girlfriends family?
Why would you want to spend less time with your girlfriend's family?
I do not like them that much
If it would please your girlfriend, you should spend time with her family. If she does not mind you not seeing them, then you do not have to.
I love her but I dislike her family and do not want to be around them.
Like I said you don't have to see them very often if your girlfriend thinks is okay but if she is not okay with that you are going to have problems. Because her family is a part of her and you might have to accompany her once in while for important vents.