Is this Poison Ivy?

I found this plant in the forrest that our yard backs onto...is this poison ivy?? Help!!

I read on this link (http://grandpacliff.com/Plants/PoisonIvy.htm) that someone posted that the edges will not be serrated and I would say these leaves look serrated but everyone I show this to says "three leaves, yup poison ivy".

Also, we had just watered some grass nearby so the leaves are wet, making them appear more shiny than they actually are.

 

This looks like a Rubus, probably a trailing blackberry. Poison ivy has 3 leaflets, not 5.

 

Thanks so much! Puts my mind at ease!!