I definitely wouldn't class that as a relapse, but as it was your first experience, there's no way of knowing what would happen if you were to try it more frequently. It does depend on the person.
I gave up alcohol and cigarettes over 9 months ago and have smoked weed twice since then (one occasion being this past weekend) I've had more experience with it than you though, as I tried it for the first time 20 years ago and enjoyed smoking it casually with friends over the years. It's never been an addiction though. It's been a fun thing to do on a few weekends over the past years and for the past 5 or 6 years I've barely touched it. I can definitely give or take it.
As lessgravity said, venturing into the unknown with addictive substances might be risky as you may try replacing one thing with another. Or even have your mind altered so much one night that it causes you to reach for a drink due to lack of clear thinking.