"Work colleague "

I don't know if this is harassment as it's only happened once to me.
I'm a 17 yr female, and my male colleague is 46, we were having a conversation in one of my breaks in the staffroom alone, and basically during the conversation he said that he went on a date with a girl last night, and he said “the smaller they are the cuter”. I'm 5"2 and work with people taller than me, even the women are taller. He's about 6"5. So there's nobody really smaller than me.
Then later in the conversation he was talking about wind. So I mentioned that I went to Blackpool recently, and it was really windy and he said “ah you’ll nearly blow over you’re so small, is that why you’ve got those in so your boyfriend can keep hold of you?”
(I had 2 plaits in and when he said 'got those in', he then reached over and without me saying he could, he took hold of one of my plaits and held it).
It didn't make me feel comfortable, so I cut my break short by 10 minutes and left to go set some sport equipment up as I knew he couldn't do that because he's not trained to safely do it.
I spoke to another colleague who told me that what I was saying isn't stupid and "it is important because I shouldn't feel uncomfortable and he shouldn't be acting like that".