SEE and SAW

Last week I bought for my son a outdoor toy. That outdoor toy call See-Saw. That mean if the kids want to play that toy must be 2 kids play together. It keep balance in the middle and have 2 seats in 2 sides. 2 kids sit at the side of the seats. Face to face opposite and they play by one up and one down. The children alway have fun with that toy.
When I bought that toy, I thought that my boy and my niece will like it but I made a mistake. I bought it and I built it with my happy face but when I built it completely and took the kids to play with that toy. Then they were enjoyed with each other. When they were happy playing together, suddenly my boy he didn't like to play that toy anymore, he said "mommy I don't like it, I don't like it" then he stopped playing. It ok, if he didn't like to play that toy, but the problem was my niece she really like to play that toy very much, so she began crying and wanted my son to play with her but my son he said "NO" so they began fighting each other and made very noisy at my home. My husband  was very angry with me. Finaly I refunded that toy to the shop...THE END.