Can std's like: aids,hpv,gonorrhea,syphlis transmit through external genital contact and no penetration -no sexual intercourse?

STDs: Yes, several STDs including syphilis, GC, HIV and HPV can be transmitted in the absence of penile vaginal penetration. Be careful, use only protected sexual contacts.

Rarely for some STDs: Thanks for your question. Very low risk for all STDs and zero risk for some. No risk -- at least low enough to be ignored -- for STDs passed by genital fluids (gonorrhea, chlamydia, HIV, hepatitis B). STDs that are transmitted skin-to-skin (herpes, HPV, syphilis) could be transmitted, but very rarely even for these. I hope this helps. Stay safe!