My boyfriend got strep on his penis..how contagious is it .and how would he get it in the first place?

Streptococcus is a common skin bacteria so there is nothing wrong with that. Most people at your age has exposed to Streptococcus species or these bacteria are already a part of your oral or skin flora. Take care.

Strep is a kind of bacterium preset on the skin or acquired from some object and may infect. It is not contagious if you do not have a cut surface or wound. Recommend refraining from sex till penis is healed.