• Seduction and Femme Fatale trope

the player needs to give consent before the character gives consent

players rolls against the dm players don't get to roll against players

if the rogue wants to steal ring from another PC, i ask the player how they feel about this situation before allowing the rogue to make a roll. If the player of the target doesn't want it to happen, a roll does not occur.

Intent Matters

I had a new player say, "I want to flirt with the bartender to see if I can have sex with her." I had another player say, "I want to flirt with the bartender to see if I can get information from her about [xyz]." Which one do you think was invited back?

One of these statements doesn't do anything besides disrupt the game and potentially make the table uncomfortable, the other progresses the storyline.

"Do you want to take this upstairs [or somewhere more private]?" is a Persuasion check to get more information from someone your character potentially finds attractive. "Do you want to take this outside?" is an Athletics (or Intimidation) check to see if you win a brawl and get information from the local drunk.

You don't need to roleplay anything more than "You go upstairs, have a lovely time together, and you refreshed the next morning" and if everything was handled very well or the check was particular high, maybe they get a point of Inspiration/bottlecap/small bonus for a short duration (be careful not to encourage the behavior)

Romance between two PCs shouldn't be banned but they need to have consent by both parties before any dice are rolled (if it's even necessary to roll dice).

Contested Rolls Between PCs when they can't agree

The dinosaur egg problem.

I present a dinosaur egg to the party after they killed a T-Rex, the fighter wanted to destroy it but the druid wanted to protect it. After some conversation between the players (not them in character) about what to do with the egg, they could not come to an agreement. So I asked what the aggressor (the fighter in this situation) wanted to do and to describe how they would do it; once that was established, I asked the druid how they would react to it and gave them an option to roll against it.

In this particular situation, the fighter drew their bow and made an attack against the egg. The druid attempted an Acrobatics check to see if they could deflect the attack. I set a DC that was reasonably close to what would happen if the Druid used their body (AC) to block the shot. The druid successfully deflected the shot, said something to the Fighter about not hurting the egg, and the Fighter stood down.

Could the Fighter have attempted another shot? Yeah, probably but it would have hurt the table dynamics. He literally shot his shot (and missed) so it was time to move on.