First of all, tell him how you feel. You can say, “I’m really uncomfortable with you having a female roommate. I’d much rather you find a male roommate.” He may not know how you feel. He may be surprised to hear you feel this way. He may be happy to find a male roommate instead. But you won’t know unless you express yourself.
Some unanswered questions may be: How long does he see himself in this roommate situation? Is it temporary? Or is this a plan with no end in sight? Is he looking for a new job so he can afford his own place? What’s the job search plan like? Would he be willing to take a loan to support his living situation until he gets a new job? Would he be willing to get a place that is not on the beach, but cheaper, so that he can live alone?
Lots of people are being laid off these days, and almost everyone is cutting back in some way. He’s not alone in this circumstance.
But, if he refuses to get a male roommate after you’ve expressed yourself to him, then you have to decide if you want to be with him under these circumstances or not. If he’s going to put beach front living with a woman roommate ahead of in town living without any roommate, or moving in with a relative or his folks until he gets back on his financial feet, you may have found a part of this guy you hadn’t unearthed up to now.
Be clear with him about your feelings, and offer up some of these ideas as alternatives to his living with a female roommate, in order to see his true colors.