Ok. Here are some examples of Perez behaving in a way that makes him very unlikeable:
1. Intentionally antagonising housemates at quiet or stressful times (coughing, simulating sex etc)
2. Comparing Ken to cancer
3. Telling Cami Li to go faux lesbian for votes, at the same time, insulting the British public
4. Going OTT in his criticism of Katie H's affair, for attention
5. Making the Jeremy incident all about himself ("I'm scared for my safety!") without even considering Chloe's feelings. Again, attention seeking
6. Goading housemates, making what could potentially seen as threats (ie telling Ken he should be worried about his safety outside of the house in a DELIBERATELY vague and creepy way)
7. Asking to leave the house and demanding a lawyer, yet again for attention
8. Sitting on the kitchen counters after repeatedly being asked not to by Keith
9. Constant delusion and arrogance ("the British public love me" etc)
10. OTT crying every time he doesn't get his own way or things don't go to plan
Now, I'm sure there are some I'm forgetting, and I'm sure you're going to say that none of this makes him a bad person, but let's be honest, he has done nothing in there that makes him a good person and on the whole he is an unlikeable irritant who very few of us would want to live with.