Thanks for the extra information Ariel! I really appreciate it!!
The lump is something that could have many causes: inflamed lymph node, sebaceous cyst, lipoma. Because of Wesley's age and the description you gave me of what it feels like, combined with the fact he's a Cav, who are a bit famous for getting all kinds of lumps, I'm suspecting it's a lipoma or a sebaceous cyst, but I'm just guessing.
Here's more reading on lipomas and other cancers: http://www.thepetcenter.com/exa/lumps.html
On cysts: http://www.petplace.com/dogs/sebaceous-cysts-in-dogs/page1.aspx
On lymph nodes: http://www.peteducation.com/article.cfm?cls=2&cat=1614&articleid=319
The only way to positively identify what sort of lump or bump your dog has is, unfortunately, also through a trip to the vet. A fine needle biopsy (where the vet inserts a needle into one of the bumps and tries to aspirate/pull out material to look at under the microscope) will tell the vet, without question, what sort of problem your dog is having.
Of course, since Wesley has already been diagnosed with lipomas in the past, you could opt to just assume that's what this is, and keep an eye on it. If it gets bigger, or seems to be bothering him, then you can have the vet take a peek..just to be safe.
I'd also stop squeezing it. These weird little lumps have a habit of becoming "ugly"...meaning that they can sort of be antagonized into growing by messing with it, so leaving it alone will give it the best opportunity to stay small.
I hope this helps.