How they first met: They first met shortly after Alder chose Iris to be his successor as Champion and began training her for the role. Benga had stopped by to visit his grandfather and would constantly critique everything Iris did, which really got on her nerves, so she challenged him to a pokémon battle, thinking he was all bark and no bite, but was impressed when their battle ended in a draw. Their relationship started moving in a more positive ‘friendly rivals’ direction after that. 
Where their first date was: After an afternoon of training in Opelucid, Iris invites Benga to one of her favorite restaurants she always visited growing up for dinner. She doesn’t explicitly say it’s a date, but the implication is there. After they’re finished eating she invites him back to her house with a wink, saying her aunt and uncle and cousins are out of town so they’d have the place to themselves. 
When they had their first kiss: They had their first kiss when they spent the night together at Iris’ house after their first date. Iris kisses Benga to set the mood once they’re settled in her room and they continue from there.  
Who cooks: Iris is a decent cook, but Benga’s definitely the better of the two. He likes having fun putting his own twist on recipes and coming up with new ones and he has a good sense of taste so they usually turn out well. He also ends up being the one at home more, especially as their family grows, so he’s usually cooking either way.  
Who proposed: Iris.
The dominant one: They are both equally dominant which can sometimes lead to issues since both are so stubborn, but they are usually able to compromise for each other. Eventually. In the bedroom it’s the same, but in that case rather than starting arguments, it just leads to a lot of passion.  
Their favorite pastime together: They sometimes have trouble coordinating their schedules, especially since Iris is so busy as the Champion, so when they do have time together, they usually stay closer to home since it just makes things easier. Hiking is a favorite pastime since both of them love the outdoors and Iris especially loves a chance to get away from all her responsibilities and just enjoy nature. 
Who kissed who first: Iris kissed Benga.
Who is the flirt: Benga flirts more often and can be a bit crasser in his flirtation methods (sometimes he’ll jokingly smack Iris on the butt, which she then returns with more force and a smirk), but Iris definitely has her moments. 
Who is the romantic: Neither are super romantic, but it’s more that they just have their own way of showing each other affection (that is mostly teasing and might seem aggressive to outsiders).
Who wakes up first: Benga is a fairly early riser and enjoys watching the sunrise while Iris prefers to sleep in a little when she has the chance. 
Who comforts who the most: Iris is usually more stressed out from work, so Benga ends up comforting her more when she’s had a particularly trying day. Benga himself tends to be more optimistic, but even he has his bad days, when Iris is always sure to make sure he’s comforted as well. 
The cuddler: They both are fairly cuddly, but Iris is definitely more of a cuddler than Benga. 
The big spoon: Benga, mainly just since he’s taller.