My advice is to do what makes you comfortable and feels appropriate for the situation.
That said, I’ve too often erred on the side of putting other people’s feelings ahead of my own. Before wearing a thong, I usually ask myself three things:
- Is it okay to wear a thong?
- Will someone be offended?
- If so, will they complain to me or an authority figure?
I’ve written before about how I determine whether or not it’s okay, so I won’t rehash that here. TL;DR: establishments that want to ban thongs usually do, and while some rules leave room for discretion, I assume it’s okay if thongs aren’t specifically banned.
While it’s always possible someone might be offended, I don’t think it’s inappropriate to wear thong swimwear. People prefer different amounts of coverage—we can all coexist. I used to worry a lot about what other people might think; I still do, just to a lesser degree. The reality is I can’t control how others think or feel, and I try not to let that dictate what I wear.
The third question is the one that still sometimes gives me pause. I don’t care if someone thinks badly of me or shares those thoughts with others. It might sting in the moment if I’m aware of it, but it doesn’t really matter. I don’t seek out confrontation. Ideally, my choice of swimwear is met with indifference. Even if someone doesn’t like what I’m wearing, the vast majority of people aren’t going to say anything to me directly. I try not to worry about it. But what if they complain to a manager, lifeguard, etc.?
Authority figures are generally obligated to respond to complaints. If we’re in a public space and I’m not breaking the law—which should be clear about what is and isn’t allowed because it needs to hold up in court—I don’t expect those complaints to ever get back to me. Private spaces with their own rules could go either way. However, as long as I’m not flaunting the rules (i.e., wearing a thong when the rules expressly forbid them), at most I’d expect a manager or someone similar to politely ask me to wear something else. There’s always the possibility for a situation to escalate, but if it does, it’ll be because the other party is acting inappropriately. If I’m asked to change, I’ll just apologize, explain that I thought it was okay according to the rules, and agree to wear something else or leave.
No one has ever complained to me directly. On one occasion, someone complained to a manager about what I was wearing. The manager politely asked me to wear something else, and I did. Later, based on changing attitudes and other members’ desire to wear similarly minimal swimwear, they decided to revise their policy. I wear thongs at that facility regularly now.
The fact that you’re so concerned about how other people feel demonstrates empathy. I think it’s wise to consider others’ feelings—but don’t let it stop you from being your genuine self.