If she wanted to make it a regular thing, James would not only not care he'd support it.
He loved Lily, very much, but Sirius was his soulmate. Honestly, if one of them had had the right bits and pieces, James wouldn't have thought twice about the woman he'd now married.
"Well, you're welcome to do so," he said with a smile, and reached out to brush her hair off her shoulder. "But another you not doing it isn't anything to fuss over."