I think a lot ofPBTA games have romance mechanics. Monsterhearts comes to mind.

Personally, I find myself a lot more comfortable doing romance roleplay when I am, say roleplaying on a fourm, chat, roleblox, or mmorpg. Something rather informal and anonymous. But then, when I do TTRPGs, I often feel a bit more shy doing romance because I know the people I’m roleplaying with. Even If I just met the people online, it still feels a bit weird.