Depending on the circumstances it can definitely be weird.
My ex visited me, and her bf was a short drive away in the same town (almost) and she proposed staying over at mine - which I thought was a bit odd - and her bf clearly did too (without meeting me at least, but I didnt particularly want to meet him for obvious reasons and she made it seem like he expected me to go and visit - read pay homage to - him at a time that best suited him rather than both meeting somewhere neutral) as they had an mobile argument in her car. Then she went and stayed with him. I dont blame the guy, I couldnt figure out what she was up to - talking to friends it was either: wanting to see us both together so she could kind of compare us in some way, or she was playing mind games with me or him, or both of us.
Now that was wierd, really put me off the idea of being friends.
Anyway, back to OP - if there is any history of attraction or dating then I think its too much, but otherwise its unreasonable to put up much of a fuss. Even though it is different for guys because we know that there are plenty of male friends of hers who probably think about your girlfriend naked all the time.