What is this bump?

I have a bump near my frenulum, right below my glans (glands), and it is 1mm or less in diameter. I first noticed it when I was 12 years old (I am currently 20), a few days after experimenting with a friend who I noticed had an identical bump in an identical location. Six years later, I discovered that my boyfriend also had one identical to mine (before we had done anything together). He said that he had gone to the doctor about it, and they said it was a buildup of some sort, and NOT anything to worry about. However, I haven't been able to find any information about such a thing, so I've been worried. There is only one bump, and it has been the same shape, size and location on all three of us.

Thanks.

[anemonies]

Anyone have any idea? :/