Gil/arty/diar general 6 and 9, love 2 and 4
General 6 What’s their relationship with each other’s families?
Gilgamesh and Diarmuid both no longer want her to engage with her family, except for her brothers. Similarly, the Pendragons (save for Kay and Arthur) have ceased all contact with Arturia save for the occasional reluctant meet-up.
Aengus FRICKING LOVES GIL AND ARTURIA HE COULDN'T BE PROUDER OF HIS BOY FOR BRINGING HOME SUCH BEAUTIFUL (and rich heh) PARTNERS. he throws condoms and lube at them when they are over, and with scary accuracy leaves a jug of water and three glasses at their door whenever well, you know. Aengus had actually always known Gil was gonna end up as more than a fwb at some point, but Arturia was a bit of a surprise, since he thought Diarmuid was done with women for a bit there. He frequently chides Diar about his type being way too obvious, since both Gil and Arturia were rich blondes with high-class poise and a proud visage basically ingrained into their systems. (Apparenly he inherited that from him, since Caer was a blonde as well)
Donn's less enthusiastic and doesn't hound the two blondes with requests for grandkids, but he approves. (He wants the grandkids, though.) He does, however, give his son plenty of nudges to propose to them already and move on from the whole "roommates" phase.
Lugalbanda was...relieved? To see that Gilgamesh chose relatively normal people, since he was also just a humble working-class man before he and Ninsun fell in love. He was a bit surprised he picked foreigners, however he could pretty much see why Gil picked them. Gil loved his pretty things. He bonded with Diarmuid more, being able to relate to him better. They talk a lot about Gil and what Lugalbanda's life has been like considering he married into the richest family in the country.
Ninsun was a little skeptical about Arturia, because of her last name, but in no time, she was being dragged around on shopping trips and corporate meetings. Ninsun was very stern with her at times, but not unfriendly. At first Arturia didn't understand why she was being brought everywhere, then she realized the woman was preparing her for the inevitable press that would want to know who exactly her son was marrying.
(that flustered ArtDiar because they didn't know Gil was planning on proposing up til then)
General 9 Who whispers inappropriate things in the other’s ear?
Gil, because he finds it incredibly entertaining to watch his partners squirm. The chances of him doing this increase with the number of people around multiplied by his current level of boredom.
Therefore charity events with Gil's company are simply unbearable.
Unless Diarmuid is horny. It's not too often that the gentleman gives in, but as soon as he does, he and Gil ramp up the sexual tension until they literally have to book it to the nearest private room else they all be charged with public indecency.
Arturia's not one for these things, which is a good thing because the boys are easily tempted by her. During their 'honeymoon phase' after getting together, Arturia couldn't walk across the living room in a shirt and underwear without being tackled onto the nearest surface.
Love 2 What are their primary love languages?
In this world, Gilgamesh's is Words of Affirmation. He doesn't lie, he's adamant about that, and his partners trust in him because of that. He also wants to make sure they know how he feels, so: They both wake up to whispered declarations of his love in the morning, receive well-placed complements every now and then, and go to sleep with his affectionate words in the evening.
Diarmuid's is Acts, so while they were in uni, he walks with Arturia to class, insists on driving them before going off on his own, takes care of grammar-checking their papers when they're too tired, shoves Gil into bed when he's been up too late.
Arturia's is Physical Touch, which is...something she only discovered when she became roommates with them. Gil had always been handsy, but she didn't really understand why she wasn't too bothered until she made that realization. The first time she attempted to explore it further was when Gilgamesh was incredibly stressed out and hunched over at his desk.
Arturia unravelled his arms, sat herself on his lap and hugged him like a koala. (It was a suggestion by one of her friends) Of course, Gil accepted it, and she spent the whole evening there with Gilgamesh giving her a squeeze to destress every now and then. Eventually, Gil decided an all-nighter wasn't worth it, stood up still hugging a snoozing Arturia to his chest and brought her over to Diar's room to join the curly-haired one in his bed.
Love 4 How often do they cuddle/engage in PDA?
Often enough, thanks mostly to Gil.
Gil will absolutely kiss them in public. Diar will maybe go for the cheeks. Arturia will not kiss in public. They are all, however, willing to receive any kisses if given.
Diarmuid likes to link fingers, so he'd be the first to grab for their hands. Arturia's alright with being escorted or doing the escorting. Gilgamesh likes his partners close by, so its normal for him to tug on their waists to pull them to his sides if he thinks they're a little too far away for comfort. His hands also spend a lot of time in their pockets.
Thank you so much for the ask :>