When Alex agrees to let his ex-fiancé Chloe crash on his couch during her stay in town without notifying Whitney, he finds himself in trouble. Instead of consoling his current significant other, he has to cater to his ex, putting Whitney in an awkward situation. Meanwhile, Roxanne lets Lily use her apartment for some alone time with a date and ends up crashing for the night with Mark.

While trying to uncover what has been making Alex's allergies flare, Whitney reveals a heart condition that has plagued her since childhood. Meanwhile, Lily introduces the gang to her new beau, but they find that he tends to have a hard time getting to the point and Mark, Roxanne and R.J. find themselves rushing to finish his sentences.

When Whitney is contacted by a terrible ex-boyfriend who is looking to make amends, Alex warns her to stay away, but Lily encourages her to arrange a meeting. However, when Whitney meets him she finds out that old habits die hard and Alex is forced to defend her honor. Meanwhile, R.J. reveals to Roxanne that she may have a thing for Mark.