Honestly, the brother only fucked him once while Woo-yeon was officially dating, and that was in a bathroom stall while he was very clearly saying 'no' the whole time. I'd count that as non-consensual, but ML is also just brain rotted as to not realize it was cheating/rape
the uke getting upset his bf cheated on him when we was literally spreading his legs for his own brothers is actually insanzzsjshsjdjjSkdjs