Is It Okay For My Boyfriend To Still Have A Key To His Ex Girlfriends House?

He should not have the keys to his ex girlfriend's house. No need!!

No way should he have a key for his exes apartment .the only way he should still even want it is if they are still having some kind of relationship.the only other reason i could come up with for him having her key is that he has stalker issues. So I would advise if you ever split apart make sure you get all house keys back and Evan after you get the keys back change the locks.

No. The answer is NO. And shame on the others for criticizing you for listening to his voicemail. He is the one being naughty here and your actions, although maybe not stellar, should not be the focus. So messages aside, he's acting badly, he's lying to you, he's hurting you, and you should ditch the fool.

Umm, absolutely NOT!!!!! If he's going out with you he shouldn't have personal things that belong to his ex, esp not her house key! That's a sign for disaster. Tell him to give it back to her and if he truly loves you he'll do it.

Quick question--why were you listening to his voice mail?  
I understand that you're close but he still deserves and needs his privacy.
As for the key, I get that it's uncomfortable and unsettling but it is possible that they are still really good friends and that's all.  that being said if he doesn't use the key then he probably should give it back and then if she needs him to check on her cat or whatever she can just leave the door unlocked or lend him a key for a few days while she's gone.  
it's possible that the key was just a habit thing, like its been on his keyring for so long he's just use to it being there and forgot about it.  no big deal so don't stress about.  just talk to him about it calming.

lots of luck

I don't find it okay. Why would he need to get into his ex's house anyway?

So my answer has to be a no, its not okay.

HELL YES!!!! He should i would go with him and make sure he gives it back and you kno what she need to take the cat to the vet and keep YOUR man out of her life they done and over tell her to get the point...you need to act and grow up he's YOUR MAN

First of all cats are very independent unless owner of cat its out for weeks at a time .ex is just using cat to keep your boyfriend in her life .no too having key,doesn't she have a mother or family to check on cat

First of all, I don't think you should have been listening to his voice messages unless he allows you to. But, if you don't see that girl around and she is not your boyfriends friend really, then I don't think it would be necessary to check on the cat. It all depends on their relationship, how long it was, what the cat meant to him, if he's doing her a favor by looking after the cat while she was gone. You really need to talk to him about it in a calm, collected manner, or you will never find out. That will be hard if you weren't supposed to listen to his messages in the first place, but if you care enough you have to do it to free your mind of worry. I hope everything turns out alright in the end.