I agree that they are still dicks. I don't believe that joining in bullying or jeering is the only way that teens can avoid looking gay or "sissy". Bullying is traditionally regarded as a sign of cowardice, as no bully picks on someone he thinks could kick his ass, and bullies usually hunt in packs. For some reason, most teachers do not emphasise and repeat that point. (The "old" view was that victims shouldn't "tell tales" and should stand up for themselves. The "modern" view is to regard bullies as "victims" themselves, which may be why teachers don't call them cowards. Either way, the real victims are &^*%ed). There would be fewer bullies if they knew that their peers regarded them as cowards.
At least he apologised, though, and his honesty about why he joined in the bullying has to be admired. Well done for accepting his apology.