If the seme was in love with him why would he get a girlfriend???

Because they have a "brotherly" relationship. Would you tell your brother/the closest person ever that you love them and risk losing it all? I'd do my best to forget about them

i don't think that the seme actually realized that he liked the uke yet, or at that stage he could have still been attached to him as a friend, but not yet as a romantic interest. it could be that later on he realized or developed romantic feelings for the uke.

I hope that is true
That would be better than your usual coward strategy
Of 'trying to forget about his feelings '

I agree. And the coward strategy is a lot more cliche. Stories shouldn't be predictable!