>>938913050
>only problem is I don't wanna fuck up our relationship long term
>seems like the sorta thing you can't really undo if it doesn't work out
It doesn't have to be a big deal if you don't make it into one. In my experience, the most likely source of drama/awkwardness in a situation like this is the "straight" brother (you in this case) being fickle or wrestling with your own feelings of guilt or confusion about your sexuality.
Just be open and talk shit out with your brother, and it should be fine. In particular, don't fucking sting him along like
>okay I've decided I'm not really into gay shit, let's stop
>wait I'm horny let's do it one last time
>okay no more for srs this time
>...unless?
>okay that was the last time fr fr
>hey man I'm soooo drunk... let's mess around...
>fuck I can't believe we did that last night, it was the booze
>dammit my gf isn't putting out, please help me dude I've got blue balls
>oh god I can't believe you made me cheat on my gf, we have to stop
>hey bro I'm going through a break up, lemme take my sexual frustration out on you
>okay I'm back to chasing girls again byeeee
It's fucking annoying. Just keep it casual and consistent.