Grandson getting ready for bed

After a long day out, my daughter (22F) and grandson (3M) were getting ready for bed.... Grandson goes into bathroom, while my daughter takes their water bottles back to their room. Daughter steps into the hallway and we hear Grandson talking to himself (his go-to is to sing the ABC's) Daughter: hurry up and go potty so we can go to bed. Grandson: I can't get my pants off. Daughter: try again and go potty. Grandson: ok I got them off Daughter: good job, go potty Grandson: big sigh I'm getting there