男として言うけど、彼女は大切にしろ。
This translates to something like
I say this as a man, cherish your girlfriend.
Is this けど just emphatic? If it is, how can I say "I am saying this as a man, but you should cherish your girlfriend". I guess it's ambiguous in English too, but the meaning of this sentence is more "I may not know (as I am a man), but you should value your girlfriend.
Another example would be something like "I say this as an alcoholic, but you should stop drinking". This but in English creates quite a big difference in the meaning of the sentence:
A: "I say this as an alcoholic, but you should stop drinking" = "This may be hypocritical advice, but ..."
B: "I say this as an alcoholic, you should stop drinking" = "This advice is very accurate as I am experienced, ..."