How big is it? Where is it located? By your description and the fact that there is no pain, it probably is not a deep structure that is infected (like the parotid gland).
However, the duct from the parotid gland (stenson's duct) terminates in the cheek near the upper molars. It has an opening with tissue surrounding it, and if you push it will "go in" but will not hurt. This could be "it".