Here is my solution to that problem.
Remember Fable? The emotes and things? I propose we add interactions you can do with your companion for use for roleplaying. I'll list below.
All these interactions will start a dialogue at somepoint. Having so many strings of conversation it will be easy to make your character and companions say what you want somewhat.
1) Kissing
Two types. First type is a quick peck like a goodbye kiss. Use for when leaving house and they staying etc
Second kiss is a passionate Long one. The sole survivor may even say he loves him/her. Taken from dialogue as the bomb drops
2)Hugs
Because the world is a cold harsh place and even harsher without them
3)hold hand
Useful aswell as cute. Canngrab hand and drag them around if you run. Jetpacking up onto a roof? Grab her hand? She shooting at people but you want her to stop? Grab her hand and drag her away. Or take a nice stroll. Occasional drop of dialogue maybe? A bit pvssyr between the two? There was over 1000 lines of dialogue. More than oblivion and modders managed it with that Elsa of Skingrad dating mod.
4)Compliments
In dialogue you can give the generic compliments your husband /wife would give pre war For example "How did a guy like me get so lucky" etc etc.
5) snuggle
Sit next to companion and interact in dialogue. Automatically plave arm around her and they lean into you, then you can resume dialogue as normal and when you end dialogue stay in that pose tol you move.
Some of you wont understand the need for this mod. A lot of us will want this though. Oblivions "See you sleep" mod was popular as was skyrim's mod that allowed you to mimic npc actions like leaning against walls etc.
I think it would make romance in fallout 4 more realistic. Afterall people who are in love show affection. It should be here also. Plus i kinda wanna have my first kiss standing on the corpse of an alpha deathclaw. Its just something i wanna do.