If the character has title, arranged marriages will come up. Have to legitimize the heir, and all. Choose the spouse (and family!) wisely.
As adventurers come in all genders and orientations, the local whorehouses cater to all kinds, especially in the big cities.
Sometime opportunities for flings or romances happen. A torrid affair may garner an enemy, but will give you a little spring in your step (spend 100gp, +1 to saves for a month). A passionate romance helps you press on when things are grim (spend 50gp / month, +1 to saves while continuing). Details of encounters are omitted.
This has been always with PC to NPC interactions. I've been in games where multiple PCs had soap-opera levels of interaction, but those were back in the day where there were multiple DMs and 30-50 players.