I could be reading too much into the fact that Krillin and 18 aren't right next to each other like they would normally be, but... apparently in the Empress storyline, 18 fell in love with Piccolo, Krillin grew his hair out in an attempt to get Maron back because he secretly missed Bulma, and Yamcha finally found a partner he could commit to... Gohan.
Okay, not really, but still, it doesn't look like Krillin and 18 are together.