The choice of verb forms

[SARDORBEK]

Nodir and I .....for over 6 months.

a) have gone out

b) have been going out

Which version(s) is/are more correct?

I cannot understand the difference between a) and b).
Please, could YOU give a clear explanation?

Sincerely,
SardorBEK

[Alan]

Only (b) is natural.
The normal rules for use of the present perfect progressive apply here.