I almost went for one.
Few years ago, I met someone who just broke up with her gf. We became friends. Then one day she asked me to go with her to Antipolo to hang out with her bestfriend. We popped some booze and she got really drunk. Right in the middle of the night, she started doing crazy things. So her friend told me, "Ano pagbigyan na natin?" I didn't say a word. Moments later, their hands were all over each other. So, I kind of joined them. Lol. But when the friend started going down south, I was like: "What the hell? Aren't they the best of friends?" Lol. So, I stepped back and left the scene.
Parang threesome is not for me. I treat lovemaking seriously and I'm only going to do it with the one I love. I'm not going to share my girl with anyone, either. Now try eating on one plate with two other people. Tell me if it's satisfying... and hygienic. Haha. =)