Sure. They can.
The problem there is that if they really** tend to take it to the marriage level**, then what is holding up them to get married?
I know if this were a woman, she could be given benefit of doubt for not being able to make this relationship converted in to marriage, but for a man to use this analogy is simply unrealistic even in some strict societies.
‘Considering’ is not enough.
“Oh! I am thinking to get married to you..but not sure yet!” 
It is not a committed relationship what I am trying to get at.
bf/gf relationship is not a committed relationship by any means.