@jabag11 Sex with a condom is not ok.
If you have sex with a prostitute using a condom, the chances of your friend getting herpes gets much more realistic. If your friend gets feels uncomfortable for a moment, or has been drinking, and the penis is not totally hard, then the condom could slip off either fully or partially, and your friends junk could end up full of blisters and lumps. Herpes has no known cure.
By having sex your friend would also be allowing for possible genital warts, a much higher chance of HIV, and all other kinds of things. That condom would be the only thing protecting your friend from all kinds of disease.
But…
Lets forget talking about STDs and STIs for a moment, and lets look at something else. This is something I talk about from experience. A few months ago I had sex with a stranger on a beach out in Spain. I was drunk and just did it. It was protected sex, but I had been drinking and the condom slipped off either partly or fully, I could not remember as I was too drunk. It turns out I did not get HIV, I did not get herpes, I did not get any kind of STI or STD at all, but you know what I did get? 4 months of horrible paranoia infused with sleepless nights.
Just because you dont get HIV or an STD does not mean your friend will be free from HIV and STD phobia/paranoia. It takes 4 months of waiting to get tested for everything, and in the mean time you suffer psychologically.
Also, I have recently proposed marriage to my girlfriend. She wanted to know about my sexual history when we started having sex, and I had to tell her about everything. I never visited a prostitute, but I did have sex with a few random strangers in my life. To be honest I did not enjoy telling my fiance about those things, but I felt I had to. One of the questions she asked me was if I had ever been with a prostitute, and I must say I am very glad that I could answer no to her with a guilt free conscience. How much is a night with a prostitute worth? is it really worth having to tell the love of your life some day that “yea I paid for sex once/several times”. I don’t know about your friend, but if I loved someone I could not lie to them about something like that. Then what? lose someone you really care about all because of a cheap thrill. It is not a good idea.
I would advise your friend to find a way of boosting his confidence so he can get out there and find a nice honest girl that he can have a nice relationship with, rather than resorting to paying for sex. Risk of STD or no risk of STD, it is still a bad idea.