Yeah... I'd say the young lady had a REALLY flimsy "excuse" for bolting. I would venture to say that many 30-somethings have parents who are still old-fashioned about bedroom behavior. My former husband's parents were non-JWs but still put us in separate bedrooms when we visited before we were married.
If two people are in love, even having the craziest parent-in-laws can't prevent them from being together. Don't let the guilt fall on you for this.