@martyn this is a slight tangent, but: if you are at any risk of HIV transmission, PrEP taken daily is these days the single most effective method of prevention we have (even if you control for adherence; condoms sometimes get punctured or have manufacturing defects; if you forget to take PrEP occasionally, it’s still highly effective). It should be fairly easy to acquire at any sexual health clinic in Berlin.
Of course PrEP + Condom usage is more effective than either alone.