I went on vacation and found myself chasing a hottie for a couple of weeks. There was frustration as well as satisfaction. Then I came home to discover (as part of a previously scheduled medical checkup) that my PSA was disturbingly elevated. Has this ever happened to anyone? If so, did the numbers come down after life went back to normal?

PSA can be elevated for lots of reasons.  I assume your Dr would tell you that.  Even a recent orgasm can bump it up.  Just get it checked again in a while.  Don't rush to let them do a prostate biopsy.  There are informed, but controversial, recommendations against doing PSA screening at all.  Even if you or your Dr disagree, its helpful to read the recommendation to get a jist of the issues.

Even a prostrate massage close to the time of your blood test can elevate.
Also do not get your PSA taken after a BDSM session with anal.
Been there done that will not do it agai

In my situation, there was no BDSM and no anal. But every practitioner of those two arts should be read your advice.

I have read somewhere that you should not ejaculate within 7 days of a prostate exam as it can elevate the results.

There are many reasons why PSA may be elevated.  Sex causes elevated PSA levels.  You need to wait at least 72 hours after sex before having your PSA tested.  Also, prostatitis (infection of the prostate) will cause elevated PSA levels.  My PSA was once up to 6 or 7 due to prostatitis.  After taking antibiotics, my PSA went back down to 2.  It's probably best to have a second test after a couple weeks to rule out a false positive of test results.