How about "My class was cancelled, would you mind watching D for a while longer tonight, I was thinking about going to see a movie".
I still think the whole idea is clingy even if he doesn't realize it.
I think a better approach which is probably a 180 for you is "Hey my class cancelled tonight, so I can take care of D tonight if you would like to go off and do something else" Show him you are secure and confident! (even if it will be difficult for you)
TwinDad Me 39, W 36, M 11 W - MLC, WAW???? 2 Kids B/G 3 YRS Old Start of the Long and Bumpy Road..... On the verge of piecing.....a new beginning