What Are The Chances Of STDs After Non Penetrative Sex?

Hello, last night i got very drunk and ended up having a kind of threesome with another guy and girl. There was no oral sex or penetrative sex on my part that is why i say kind of, but now i am terrified in case i have caught something from either of them. Can STD s be caught through touch?? Do you think i should get tested? Another thing is i have a boyfriend and the guilt is eating me up i feel so terrible! I know its not a medical question but do you think i should confess to my boyfriend? I know it may not seem like it but i do really love him and have never done anything like this before. I hate cheaters and now i feel like such a hypocrite and dirty. i really hate myself just now i cant stop crying thinking about it.