It means, "...if you/he/she had a [male] friend..."
"Si amigo" is Spanish for "Yes friend." It is a casual way of acknowledging agreement or understanding of something.
si amigo
"Si mi buen amigo" means "If my good friend" "Sí mi buen amigo" means "Yes, my good friend" Notice the accent mark over the 'i' of Si. If the accent is there, then it means "yes" if the accent mark isn't there then it means "if".
Si vieras = "If you saw..."
there is no word si in English
'si je' means "if I" in English.
"Si te cojo" in English translates to "If I catch you."
"Si alguien" translates to "if someone" in English.
if
"Si no está en inglés" means "if it is not in English" in English.
si amigo
This is the closest translation I could get: I love you friend likes you Stabio