I didn't read the chapter since i decided to only read completely translated stuff.
I can't stand it anymore to wait and then the manga is dropped. :'(
So i'm always checking this series and I've read your message at the beginning. Then I looked through the chapter, trying not to get spoiled too much to find the empty bubble, and since i have the raws....well that's what happened. ^^
But thank you for your efforts! <3
In the blank bubble, he just repeats his words "I love you"...
well not exactly cuz in the previous bubble it is written "omae wo aishiteiru" (omae=you, ai=love). And in the second bubble "aishiteiru" and that's all.
But it's a common thing in japanese to remove the subject and all when we already know who/what we're talking about.
PS: I'm a noob at Japanese. But I heard that sentence a lot in anime... so... well I hope I didn't get it wrong! ;p