[sharky]

You're probably in good shape being a lap swimmer. I'm sure it will come up in conversation that one of the ways you stay in shape is lap swimming. And, no news flash that lap swimmers often wear a speedo. So the fact that you wear a speedo to work out shouldn't come as a surprise. Now by the time you go on vacation, if she is unaware that you would prefer to wear a speedo on the beach or at the pool, you could just wear board shorts over your briefs. But since you are a distance swimmer, take the opportunity to pull out your googles, tell her that you are going to distance swim for 20 minutes, take off the shorts and go for it. When you get back to your chair leave the shorts off until you've dried off. If you are in good shape, she may just encourage you to keep the board shorts off to get a better tan. (Another approach could be to wear the board shorts in the water at first and then come back, take them off and tell her that the shorts are creating too much drag and throwing your breathing off...which they would do.)

My wife pretty much accepts my wearing a speedo. However, while I wear it in the water...swimming and snorkeling.... and in a lounge chair (for the tan), I do not generally parade around in one...I also personally feel more comfortable taking the opportunity to distance swim first. I think people are more accepting of swim briefs if they see you are actually a serious swimmer.

As a last suggestion I'd wear a solid dark or panel suit (black or navy). They look good and understate. A fun pattern or white would be a definite mistake...unless she picked it out. Good luck! (I do hate wearing board shorts in the water....but tolerate a TYR nylon drag short -with the liner cut out- on top of swim briefs....at a family beach.)