If so much 'intoxication' can be cleared with a kiss, I can only imagine how much would be 'released' if it was all built up in his crotch. ( ͡° ͜ʖ ͡°)
But seriously, though, don't know what the bro really thinks about his sister, but he really needs to reevaluate how he has treated her up to now if he thought all of it was out of love. That was not how I saw it from my account.