Forbidden love

Killua was raised in a homophobic household with an abusively strict father who instilled values that killua couldn't do anything that would make him gay. Killuas father continually instilling in him the shame men should feel for being gay is part of the reason killua can't accept his own sexuality. He only hooks up with Gon in private despite Gon's obvious attempts at public displays of affection, and despite a semi-platonic relationship with Gon, Killua still hooks up with women publicly to keep up his appearances. Added of gon having his own problems that can potentially ruin what they have. It's then they choose if all this is worth the consequences.