What did dr. drip say to the bleeding kid who refused to get stitches worksheet answers?

He said suture self

This is a joke, more precisely a medical pun. It sounds like suit yourself as in it's alright, if you don't want stitches then fine, however, it is written as suture because suturing is ensuring that a bleeding area is closed down and no blood can flow from it, which is stitching in essence, so he's telling him suture self as a joke.