SO: Normal?

I'm an older sister. I remember one day when my sister and I thought that we should practice kissing. I'm 4 years older and I think I was like 7-8 when this happened. Then (I don't remember who suggested it) but we tried tongue kissing once and decided it was icky and never tried it again.
That post made me think. Was I wrong? I don't remember if I started it or not (probably since I'm the older one) it's never been mentioned again so I don't know if my sister remembers it. What should I do?