It shouldn't surprise Sparhawk that Martel is living in sin (or what most of the clergy would term sin), but it doesn't bother him.

What is surprising to him is that he's glad Martel has found someone again, and is happy. Wanting his estranged brother to be happy is an novel sensation for the broken nosed knight, and he takes a moment to assess this.

The comment about the lifespan mostly goes over his head though. He'll probably remember it later.

"Were we ever that determined I wonder," Sparhawk muses, unaware that while he's thinking about Martel being happy, his tone has slipped to something resembling friendly, rather than civility. "Khalad is the same way."