It's not that April doesn't love Roger. It's not that she'd leave him for Maureen. But nights when Roger's at some club, when Mark's gone home to visit his mom, when they're just home alone together, for whatever reason, somehow it always turns into giggles and kisses, one of them pinning the other down on the couch and touching her here, and here, and here, while giggles turn to gasps and whimpers.
April loves her, yes, but not like she loves Roger. Maureen's safe, and people would laugh to hear that, about Maureen, but Maureen's not going to come home high at 4 AM, Maureen never kisses too hard, never leaves bruises where her hands grasp, and when Maureen sleeps with someone, she always tells April about it, and neither of them much care. It's not that she doesn't love Roger, it's just that she knows Maureen won't break her heart.