do you think hayley is in love with klaus? and if she is in love with klaus, why did she have an affair with elijah and not give klaus a chance?
Ah this is an easy question. The entirety of Klaus and Hayley's relationship is governed by two factors, circumstances and timing. Try and put yourself in Hayley's shoes. She sleeps with Klaus ends up pregnant and doesn't know it until the witches kidnap her. Now the only person she wants to see is Klaus but he doesn't show up, instead Elijah does. Hayley is obviously freaked out by the whole ordeal and Elijah comforts her. Now when Klaus does show up all he does is throw accusations at her of sleeping with another man and says to her face to kill her and the baby. Even when he accepts the baby he only gives a damn about the child not Hayley. Upto that point only Elijah has shown genuine concern towards Hayley herself and not the baby so obviously she starts to like him. I'm season 1 there are definitely sweet moments between Klaus and Hayley but Klaus always alternates between hot and cold. He is kind one time and absolutely hostile the next so she naturally finds comfort in Elijah and starts a relationship with him. Why cause Klaus doesn't give a damn about her, only the baby and he is off with Genevive and Cami in s1. Now Hayley truly realizes she loves him when he is ready to sacrifice himself for hope but the problem is by the time they both realize it that is in season 3 they are already in too deep with Cami and Elijah and Jackson. Then Cami and Jackson die and they both bond over that but Klaus pushes her in Elijah's direction in season 3 just like he pushed her to Jackson in season 2 for the sake of having a pack to rule over. The writers themselves screwed everything by not properly setting the pace for Klayley and instead chose other ships.
So to answer your question yes Hayley absolutely loves Klaus given how many times she prioritizes him over everyone else wants him safe and whatnot. When Hayley wasn’t ready for a relationship with Klaus and actually wanted Klaus to be kind, to give him a chance, he was not. When he was kind later, and she tried to give him a chance he shut the door in her face and considered her to have no feelings for him (I thought i was out of the running ages ago he says to her while she writes the letter in season 1) and hence pushed her to other men while trying to strategically tie her to him. Because to Klaus Hope and Hayley are package deal, amd that's non-negotiable. He wouldn’t take one while giving up the other. He doesn't give a fuck about anything else. His thought process goes like this: I can't have her she likes someone else but I will die before I let her go so better she be with my brother and they both stay. Two birds in one stone.
Hayley's is like this: Klaus is the father of my daughter and I want him in her life, that’s non negotiable but he doesn't love me like that and Elijah does and I have already reciprocated to Elijah so I will stay with him.(she only married Jackson to fulfil Klaus's demands and that also gave her control over the pack. Again two birds in one stone. She can have Klaus and the pack like that)
Yeah, it's hell when you think of it but the fact that they will go to such lengths to be with each other(in each other's life) should be evidence enough of love.