I shared an apartment with my wife and her classmate/friend one summer. She was decently attractive but a total slut. She was all about anon sex with no protection, had constant yeast infections (or something else, she always complained but never went to the doc), etc. I wouldn't fuck her with someone else's dick, seriously. My buddy came over one night for a party and I told him, as a friend, that he shouldn't fuck her. He was bewildered, but when I explained why he took my warning well and thanked me for saving his dick
She tried to hook up with my wife while I was out of town for a summer job. My wife called crying when she was alone and I had to quit my job and move back. She was scared of psycho slut LOL. We kicked her out a month later.