Help

I’ve been trying to find a specific manga or manwha which I thought was bj Alex but after reading the whole thing again it was not. The only thing about the manga I can remember is there is a flashback about the Mc and his sister sitting in the mc’s room talking about he should play all his cards and he should keep one hidden that card being him being gay because every thing else about him is perfect and the mc’s sister says some sort of poker reference about how one card can ruin like your hand. Anyone have any ideas on what this could be?