Bikini Bottoms

[Torchwatch]

There appears to be overlap in the crotch seam widths of men and women's suits, ie the narrowest men's suits will be narrower than the widest women's suits. Any woman's suit in this overlap area would be wearable by a man who can wear the narrowest men's suit.
The size of men's balls varies, as the radius increases the surface area increases exponentially (work out the maths yourself), whether the stretch in the fabric can securely accommodate this increase in surface area decides whether you can wear that bikini in public. Similarly a low cut front waist may not safely contain a larger cock.
Porn went through a phase of only showing guys with massive cocks and balls, everyone aspired towards huge size and became ashamed of their own more moderate equipment. Wearing a tight and tiny swimsuit shows that you accept what you have been given, unlike the guys in the board-shorts who claim they wouldn't fit into speedos.