Wilder's first joke

Wilder likes to ask to go outside all the time, saying 'outside' (and perhaps shoving his or your shoes into your hand). However, he also knows that bathtime is the end of the day and bed follows. So one day this week when he was in the bath I asked him if he wanted to go outside, and he looked confused, then he laughed as I said 'that's so silly' and now he laughs everytime you say 'outside' while he is in the bath, and says 'outside' himself while he is in the bath, and then waits for you to laugh and joins in. It is very funny.