I tell my nephew that maybe means maybe yes or maybe no so I do t feel like a maybe is a lie. If the weather had cooled down you might have changed your mind so it actually was a maybe.
I can't stand the "we never lie to our kids crowd". We lie all the time when kids come home with crappy are or ugly jewelry we don't tell them it's ugly. We say it's beautiful and thank them. Plus sometimes the lies let kids be kids for just a little longer so I don't see the harm. I mean I believed in all kinds of stuff when I was a kid and it didn't damage me. Santa, tooth fairy, mo steers in the vents to keep kids from playing with them... It's all good with me. The only lies I don't tell are things like I'm going to take them somewhere or do something when I know I'm not. Those kind of lies damage a kid more then believing in Santa ever will.
Of course this is all just my opinion. lol