My boyfriend joked about cutting and I used to is that a deal breaker?

[MaggieCarver]

I have been dating this guy for a very short period of time, but we went on our first official date and spent the whole day together outside of work. However he made a joke about cutting. He was putting the back of his hair up in black bands and then I'd take them off and so I had quite a few on my wrist. He joked that if I had more people would assume I cut. THing is is that I did used to cut and don't want to tell him yet, because I'm doing soooooooo much better and just want to move on.

Is it too mch to deal with?
Should I tell him?
Or should I forget about it?