I was briefly involved with a woman who was engaged. This was..more than two decades ago (now I feel old). I had taken the semester off from school, moved to Alabama & was living with my aunt, uncle, and younger cousin. My older cousin was getting married, very informal affair (courtroom, bride's sister wore a t-shirt with a pack of smokes rolled up in the sleeve). Met an attractive girl at the reception/party, had a nice time, she wanted to hang out some more. I went over to her house a few times the next week; no sex but lots of fooling around. It was miles and miles upon miles away from the blue-blood New England three dates till the first kiss I was accustomed to, so it was lots of fun, and she was obviously very into me. Finally, after a week +, my older cousin stops by and says "just so you know, her fiance is in basic training right now."
She didn't wear a ring and hadn't said a thing about it. I told my aunt that I wasn't home if she called. And that was it.