Kitten Peed on me

I brought these two home yesterday and overall it’s been really great! They hid under the couch for a little bit but they came out to eat and play last night and this morning. They’ve both pooped in the litter box too which was great. A few minutes ago the white one (still deciding on names) peed on top of me. I had a blanket on my legs and it peed right on it. I didn’t notice until a few minutes later so I wasn’t sure how to go about it. Had I noticed right away I was of been firm and said no and would have picked him up to remind him where the litter box is.

I’m hoping this is a one time thing but if you have any advice to hopefully not have it happen again please let me know.