While on holidays in my parents place in Portugal. I always take an early morning swim in my speedos when its quiet. I can usually see a friendly neighbour of ours walking around his house and front garden in his speedos beside his family, watching me take a swim.
Once he sees me go for a swim, he goes back into the house and changes into board shorts before coming out and joining me as the only other person in the pool
He never takes those 10 extra steps into the pool in his speedos and always changes into board shorts before swimming. Plus I've never seen him swimming whenever I'm not in the pool in my speedos.