If you are on a swim team you could wear a skirted suit as a drag suit, that way you shave even more time at meets... If you just mean in a local pool or in your back yard, of course. The only thing...
There are many possibilties, and it depends on the guy-
here are some possibilities
1. they like you and are comfortable with being so close to you
2. they are over- affectionate
3. they are sexually...