Kissed a colleague on the lips, is it an issue?

Basically, a group of colleagues were all at the pub having Christmas drinks. I'm the youngest of us all, in my mid-to-late 20s, everyone else is around 40+. There's a lady there who is around 20 years older than me who I've always thought was attractive and I have been told by someone that, when my girlfriend broke up with me, he overheard her saying, "if I was 20 years younger..."

Now this isn't a should we get together or a should I ask her out question, firstly, yes, I find her attractive but I totally agree with what she supposedly said about the age gap, it's too big a gap. Secondly, from what she supposedly said, her intentions are clear that she doesn't want anything with a younger guy anyway.

Anyway the story is, throughout the night one conversation was about my beard, which is quite long, all the ladies agreed I should shave it off, while the guys said I shouldn't, so i told them it was soft, due to what I use on it and a few of them felt it and agreed. Then at one point when she was sat next to me she pulled my beard so that our faces were close together and laughed. She did this again near the end of the night and then not long after I just went forward and kissed her, with a quick-ish peck on the lips. Obviously drunk I can't remember what happened next or how she reacted, whether she laughed or what but there was no shouting or anything, I'm quite sure. I think she was slightly surprised.

But yeah, I am generally pretty quiet and get on with things and I am really hoping this doesn't turn into some big thing, I also hope I didn't upset or annoy her. I just hope it is forgotten about or if it is mentioned it is just a quick private word between us in a jokey way. Am I thinking too much about this, was I wrong to do this in the first place and what, if anything should I say to her about it? As far as I'm aware we are both single.