No; in some cases, such as HIV/AIDS, you may not even be aware you have the disease. That's why people should be tested if they have had unprotected sex (and even such protection as condoms is not 100 percent effective).
Yes and no. The chances of becoming pregnant are slim but there is always the chance of STD's with unprotected sex....
You don't always have to have symptoms to pass on an STD or HIV/Aids - if you have had unprotected sex with others there is always a risk!!! Always use a condom. Answer Yes. It's NOT a matter of cleanliness. STDs are passed on by various fluids produced during sex itself (and shortly before) and/or by intimate physical contact, which may include unavoidable contact with fungi and the like during sex acts. Always protect yourselves.
Do you mean an STD as a sexual infection? If so, it didn't "come into practice" it has always been around and spread ( still is spreading) with unprotected sex.
Sex does not change the body unless you get a STD or pregnant and then the pregnancy or STD make the body change.
Sex. It is an STD.
are you for real? of course not!! (although if you never pee again after having sex once then that is a problem but it doesnt mean you have an std!)
STD transmission occurs from any type of sex with an infected person including genital, oral, anal, and sex toys.
Some say it's full of protein, but there's always the risk of STD in any unprotected sex.
Nothing that I can think of Nothing is wrong with sex(besides getting and spreading STD's). Sex is a wonderful thing regardless of what age and religion you are. Although being under 18 is too young (at least be in high school) and if your religion says sex is wrong if you're not married then don't defy it.
Unprotected sex.
If you or your partner have NOT engaged in any sexual activity where fluid has been present, then no... you are your partner will not have an STD from having oral sex. If you or your partner have NOT engaged in any sexual activity where fluid has been present, then no... you are your partner will not have an STD from having oral sex.
The same way you catch an STD from anyone else. It's all about unsafe sex.