sleepovers with guys

If anyone here is a parent I really need to ask a question because I'm kinda really irritated right now. So my friend and I were talking about spending a weekend at her cottage this summer with two of our friends who are guys. Well when I brought it up with my mom she said no if there were going to be guys there. She said it's because she loves me and things change but I don't understand why parents have an issue with sleepovers as soon as a guy is in the picture. If anyone can help me I would really appreciate it because I'm upset.