She's really desperate for them never to be apart! She wants them holding hands forever. I guess trying to reduce sweating is a good reason to hold hands.
After the time travelling plot twist, I can't help but think of every reason that she denies, has got to do something with the cause of his death in the future.
Just read through all of this so far - the time travel twist really elevates it above all the rest of the self-imploding tsundere comics out there. A fun read so far.