Primer mottling, is it getting absorbed into the wood?
Supele has a lot of natural oils in it, similar to some types of Mahogany or even Ipe, making it great for outdoor applications, including decks and even boat building. However, because of the natural oils, it will repel finishes and give the finish you described (a picture might help). Try sanding it smooth, then wiping it off with mineral spirits before attempting to paint again.

This still might not solve your issue and a coat of shellac as recommended by @jbbenni might be necessary to seal it prior to painting.