Paris has been cracking down on both male and female escorts lately so they are much, much harder to find than they used to be. This is because Dominque Strauss Khan, an enemy of the current government aparantly owned a part interest in many of the straight and gay escort services.
At the moment it's illegal for the escorts to advertise on Gay Romeo and similar sites and the police are checking so many are backing off.
What's not illegal is for a self employed escort of either gender to meet new clients in a bar or any commercial space that serves alcohol. So, the escorts tend to work the bars and clubs now rather than advertise. That said it's illegal for you to ask an escort for their services. But, it's legal for them to offer their services. So, you pretty much have to chat up the guys you think might be escorts and wait for them to name a price.
Your other option is just to take a 45 minute flight to spain where escorts are legal and plentiful.