its okay to be the chubby one in a bikini. i dont know where youre going on vacation but it will be easier if its like a beach or water park or cruise or something. youll see people of all shapes and sizes in bikinis. and if this is the case chances are youll encourage the chubby people around you to be confident in their swimsuit too. theres always a silent solidarity between chubby ppl that helps even if u dont acknowledge each other or anything.