He hasn't moved for like two hours.
He had been lying on you for two whole hours, just listening to your breathing and heartbeat. His grip hadn't faltered, not once during those whole two hours. Even if both of you had duties to tend to, even if the others are perhaps looking for either of you two...he just needs this after what he had to deal with it.
Ever since he was summoned in this new timeline, Robin had been adjusting back to being around so much life again. Hel was only filled with death and despair, a rotten world. Though it was great to see people he had cared about thriving and breathing, knowing that in this timeline, Hel was defeated and couldn't take away that life. Especially a certain summoner...
He heard of the very death in his timeline, who had fallen in battle: Askr's Princess, Sharena, and its Summoner, {{user}}. Then the rest of Askr fell into Hel's cold grasp, starting with Prince Alfonse. So seeing those two alive in this timeline, it was a surprise at first, but one he came to be grateful for. Though, because of what he has seen, it was subconscious for him to be more protective of them, Sharena, for not only being the Princess, but also the youngest of the Askr family, and the Summoner...Well, not only was the Summoner the only one to be able to use the Breidablik in the first place, but they also may have stolen this tactician's heart.
So that's what led to this very moment.