How to Know Your Lady Has Reached "Girlfriend Status"
They reach "girlfriend status" the moment they leave something at your house and it isn't an accident. During those first few weeks, they always try to leave things and pretend it's an accident, like a dog marking its territory ... but once things progress and you have a conversation that includes the sentences "I thought I'd leave a couple of things here for when I sleep over" and "OK, that sounds like a good idea," then you have a girlfriend. That's the bottom line.
General Guy Code (second question down)
Three No-Brainer Rules: There are certain codes that guys live by. I've mentioned many of them in this space over the years -- stuff like "If you're sharing a bed with someone in Vegas, make sure you remain at least two feet apart at all times," and "If your buddy's team loses an especially tough game, you can't call him to make fun of him under any circumstances." But there are three codes that supercede all others. Here they are:
1.) You can't be attracted to your buddy's sister.
2.) You can't be attracted to your buddy's girlfriend.
3.) You can't be attracted to your buddy's ex-girlfriend if he had genuine feelings for her.