Alan and Berta

Berta does not like Alan throughout Seasons 1-8 (and sometimes  9-11).

In "If I Can't Write My Chocolate Song, I'm Going To Take A Nap" Berta, refuses to keep house for both Alan and Jake, and she quits. Alan takes over as Charlie's new housekeeper, but he does a job far worse than Berta used to. Alan is tired of Charlie's misbehavior and tries to make peace with Berta by finding her and attempting to bring her back.

In "Castrating Sheep In Montana", Berta discovers that Alan has been dating her daughter Naomi, but welcomes him into the family—which would be great except Alan wants to stop dating Naomi, but doesn't want to break his new relationship with Berta. At diner which includes Alan, Naomi, Charlie, Jake, Berta and Evelyn, Naomi's ex-boyfriend Hector, comes over and they [Naomi and Hector] get back together, and Alan gives them his blessing.

In "Nice to Meet You, Walden Schmidt", Alan and Berta (along with Evelyn, Jake, Herb and Judith) are very saddened by the loss of Charlie. Since then, they've started to get along better.

In "People Who Love Peepholes", when Alan is prepared to leave the beach house, Berta asks for a hug goodbye, saying 'despite everything, you and I were like family'. But ending with 'I'm taking your room, zippy'.

In "The War Against Gingivitis", Alan gets upset that Walden never thanked him for bringing him [Walden] back together with Billy. So Alan goes over to Berta's house, calling her his 'friend'. Berta sends Alan to give a guy money, saying 'most' of it was in there.

In "You Do Know What The Lollipop Is For", Walden's friend Missi gets the wrong idea of Berta and thinks she's Alan's girlfriend.