Mack's first drink was Root Beer

I can't believe my baby went from only having breast milk to 5 shots/drops of root beer.  Not to mention I had no idea that he was getting root beer.  I have pride myself on the fact that he has only had breast milk and I have look forward to his first reaction to tasting something else.  Now remember he is my first so every milestone is a huge deal!  This all happened on Friday October 9th.  Mom and dad came to town to hangout.  I had gone to Jimmy Johns and bought us sandwiches.  I had root beer to drink and mom and dad had coke.  While we were eating I told mom about how her mother (grandma Uleda) said that she drank root beer as a baby.  Later on my mom and I were outside messing around in the yard and my dad was inside with Mack.  I had not drank all my root beer so it was just sitting there near the two of them.  They were only alone for about 15 minutes, but I guess it was long enough to experience root beer.  When I got back in the house I looked at Mack and he had brown stuff all over his cute blue polo outfit.  I immediately asked dad what was on him.  Mom was holding him and dad just briefly said "root beer"and strolled away.  "What root beer" and said in shock.  At this moment I did not know if I should make a big deal of it or not.  I truly just did not know what to say.  I had a lot of questions going through my mind like... did he like it? what face did he pull? how did he react? how come you let me miss this? aren't you worried if he had a bad reaction? what kind of damage can this do digestive system? My mind went on mental  meltdown and I said nothing.  
Now two weeks later I sat dad down wanted to know the entire story.  I guess Mack lunged toward the drink and was a bit fussy so dad decided he might like it.  Also dad said that if he did like it he would remember that he was the one who let him taste it first.  He was creating a memory.  I suppose they bonded and dad wad pleased that he was able to have this first moment with him tasting something other than breast milk.  Dad said that the first sip he pulled a face but then he wanted more and was excited kicking his legs as he filled the straw back up for him.
I am glad that he liked it and that he did not have a bad reaction but I am his mom and I am putting down my foot.  I have informed my family that no more drinks of any kind.  He is back on just breast milk.