i heard from ppl dat this happens, is this true or just a superstition??

I can 100 percent confirm this is a superstition.

Sexually arousing thought does not secrete any chemicals that affect pimple growth or brightening of scars.

Pimples are common among teenagers, and are the results of oil/dirt buildup that blocks pores.

I've known some of the horniest mofos with clean faces. Rest easy. No, but stress does which can very well be caused by sexual and social frustration. Get counseling and change the subject in your mind until a better time. Absolutely not true. Just some bizarre myth. i really dont think so.