What if I have an STD? :/ ?

It doesn't matter that he didn't ejaculate. The penis excretes fluid during arousal and sex, before ejaculation. This is called "pre-ejaculate." It is just as infectious as ejaculate in terms of STDs. And of course there is also the issue that some STDs like Herpes, Genital warts, and nonwart causing HPV infection are transmitted through skin to skin contact, not fluids.

Go talk to the kid and try to get answers. Next take yourself to the Local Planned Parenthood, Free clinic, or cheapest low income clinic you can find. You do need to get tested. But be aware that infections like HIV can take up to 6 months to show up on a test.

And maybe you should take to your parents about this. Something tells me that if a 15 year old is drinking heavily and having unprotected sex, there are other problems involved. Even if you don't want to tell your parents, you've got to get tested. This is no joke. Some of these infections can kill you; the sooner you know, the better chance you stand of either fixing it, or prolonging your health.

Rumors usually don't have a lot of truth to them. Stds can be passed on even if you didn't ejaculate (come) inside her, they can be passed on when your genitals meet your partners genitals.

Keep an eye out for any unusual symptoms occurring below the waist. If this happened last night, then you should wat at least 3-6 weeks before you get tested. If you get tested too early you can have false negative results.