Answer :
Romeos heartache will go away when he meets another girl I'm pretty sure
Romeo’s heartache will go away if he meets another girl.
In Benvolio's lines he's basically telling Romeo the best way to get over one girl, is to get another girl He tells Romeo "take thou some new infection to thy eye/And the rank poison of the old will die." He says if you find some other girl whose beauty is infectious then the old love that poisons you will die. This ends up being true. Romeo attends the Capulet party in hopes of seeing Rosaline but he sees Juliet. Juliet makes him forget all about Rosaline and he falls completely in love with her.