You CAN be friends with both sides. You don't want to ruin a friendship over peer pressure. From either side of this.
Explain to them all how you're a mature, grown man who isn't in grade school anymore and doesn't give a crap what their catty differences and disagreements are.
Explain that you enjoy being friends with all parties involved and see no reason not to hang with one and/or the other from time to time.
Your two "very close friends" should be helping to smooth things out as well. But again, since you're NOT a 12 year old girl, who cares if they do or not. It's college.....cut the drama and make with the wild partying. Sheesh.
Hope that helps dude.