How skinny should you be to look attractive in a bikini?

I am known by my friends for having the prettiest eyes and face, but how skinny to pull off a bikini? I hear from many people "as long as your comfortable in it that's all that matters", "you must be model skinny", or "just get one that fits" how much pudge should u have to look attractive in one(I heard a middle amount--not pot belly, but not flat-- how much should that be?)? A friend told a thumbs length while lying down on your side--from tip of waist to tip of thumb--? I also heard no pudge and index finger length from tip of waist... Also I'm "5 2", medium framed, 125lbs @ night time, and female(obviously haha)... Is that decent? Am I fat? Ugh, also in some mirrors I feel really attractive in bikinis, and others(like the ones at target with about 5 in the room) not as much...