No FUPA is not what results in cameltoe... too tight pants result in cameltoe and even a size-0, FUPA-less girl can sport a cameltoe. You can see some super (well, not really) pictures at
www.skintightcameltoe.com.
I tried to find you pictures of the FUPA on the Internet, to no avail (I did find some horrible other pictures typing those words in though). Basically it is fat below where a belly is (right in front of the reproductive system).
I suppose a guy could get fat here, but I have never seen it... they just get guts. So, no, I do not think a boy can get a FUPA!