This has been done on other forums so I am thinking what the hell... you tell me Who is the A_hole. I welcome all feed back and further points of discussion (contention). 
Our 3 boys have tutoring sessions @ 5, 530 and 6 on Thursday. My MIL is gracious enough to get 3 boys off bus and feed so that I can work come home and take 1st to tutor session @5. So, I come home @ 440 and start moving boy #1 towards shoes/coat on time to leave in 2 minutes to get to library for tutor time(takes 10 min to get to library at that time). 30 seconds later MIL stops all progress and pulls out ice cream treats for all 3 boys. Long story short we get to tutor 10 min later(Still paying for full 30 min).
Am I the Ahole because I am pissed that this act of spoiling the children making them late for their paid tutor session was disrespectful of our plan when it was VERY CLEAR what the timeline was set for the evening, or was she the a_hole to give the kid an ice cream sandwich after I had already clearly given the shoes on /coat on time to leave instruction.
PS I give Grand P's alit of leeway and discretion to spoil the gkids(that is their job, and the have earned it) .
Please help me understand who was the a_hole.
Edit: forgot to mention that there are now 6 1/2 gallon containers of ice cream and 4 boxes of ice novelties in my freezer now as a result of said MIL( 2 boxes SpongeBob and 2 boxes of M&M cookie sandwiches, q 6x .5 gallon tubs)

Our 3 boys have tutoring sessions @ 5, 530 and 6 on Thursday. My MIL is gracious enough to get 3 boys off bus and feed so that I can work come home and take 1st to tutor session @5. So, I come home @ 440 and start moving boy #1 towards shoes/coat on time to leave in 2 minutes to get to library for tutor time(takes 10 min to get to library at that time). 30 seconds later MIL stops all progress and pulls out ice cream treats for all 3 boys. Long story short we get to tutor 10 min later(Still paying for full 30 min).
Am I the Ahole because I am pissed that this act of spoiling the children making them late for their paid tutor session was disrespectful of our plan when it was VERY CLEAR what the timeline was set for the evening, or was she the a_hole to give the kid an ice cream sandwich after I had already clearly given the shoes on /coat on time to leave instruction.
PS I give Grand P's alit of leeway and discretion to spoil the gkids(that is their job, and the have earned it) .
Please help me understand who was the a_hole.
Edit: forgot to mention that there are now 6 1/2 gallon containers of ice cream and 4 boxes of ice novelties in my freezer now as a result of said MIL( 2 boxes SpongeBob and 2 boxes of M&M cookie sandwiches, q 6x .5 gallon tubs)