Is hiding stuff in the store stealing

Im sure Im not the only one that does it. Today I was in Walmart for some things I needed and saw some things I really want. I am limited on cash until I get paid on friday and it won't many left so i stashed it all behind a big box in the baby section. This lady (she was a customer) apparently seen me and went on and on about how it is stealing and immoral to do stuff like that and she was going to go and find the manager. When she walked off i grabed the stuff found a new spot and carried on with life. I have every intention of coming back and paying for it...this not my first time hiding stuff. Is it really stealing?