And he just told me that I wouldn't understand?

I've tried asking again and again, and everytime he says I wouldn't understand and then says "You can do it anyway, I'm not telling you not to, I'm just asking."

How freaking condescending can he get? I get that he's 19 years older and probably feels he has a wealth of experience and that you should defer to his wisdom, but...

This is fucking ridiculous.

He might have a legitimate concern. I see another commenter has raised recent health scares raised with certain pools, which might be one thing. Or perhaps he's become jealous and doesn't like the thought of people seeing his wife in her swimwear now. That's all conjecture.

What's not conjecture is the fact that he's being ridiculous. This is your husband, and he can't even communicate a simple concern with you. What happens when it's not about going to the pool but some other aspect of your life he has firm opinions about?

When he can actually talk to you about this and not just play mysterious or condescending about it, then give him an ear. Not before.