Sirius nodded, that was all he needed, just that promise, the rest didn't matter. Anything else could happen so long as James was safe and alive, he could make it through anything as long as that remained constant.
"We will." he murmured in agreement against James' lips, his hips rolling up to press against James as he moved on top of him again. Rolling onto his back and holding James tight, this was all Sirius needed - James there pressed against him, until there wasn't room for anything else in the world between them.
"Gods, I love you." He still didn't say it often, but it didn't hold that same fear of the unknown those words had always held in the past. But there were times that he needed James to hear the words, not just show him as he did with most things.