Does my husband love his affair partner?

I caught my husband having an affair with a girl last week. He was confused. He is sorry. He knows what he was doing is wrong but he still doing it. He has enough time to stop it but he makes it worst.
Can any of you out there share your experience and thought with me.
My husband said he has feeling for this girl. He never thought he could end up having sex with her. He always talked about us ( me and my son ) with her. They both agreed that they should not go any further than just friend. My husband did not tell her his real name. He never shared his work with her. He knows what he should and should not tell her. He completely knows what he was doing.
He said he likes to talk to this girl because she gave her good feeling. He feels happy talking to her. He feels being admired and he got full attention from this girl. He said he gave her positive and motivation talk when she was unhappy. But he, he did not share too many of his story with her. Within two weeks, they got closer. He was sending message to her more than to me. He rather went lunch with her than with me. No matter how busy and how tired he was, he will still went to meet her at her working place before he came back home. When my husband suggested they should stop going any further, she agreed but she offered sex to my husband. Well, my husband never had sex with any other woman before except me. So I guess he just can’t resist.
After the first sex, he wanted to confess but he dared not. Two days later, he went to see her again asking to stop. He said the girl requested for another sex before break up. Ridiculous, right? Anyway, they did it again. So… to not hurting the girl, he can’t just left her. Two days later, he went to see her again and I guess they have sex again. And another two days later, she called my husband to pick her up after work. Unluckily, he falls asleep and luckily, I saw the message and that’s how I caught him.
I texted her asking her to stop contacting my husband, she said okay. She said he is a good man and she doesn’t want to bring harm to us. But three days later, she called my husband again. My husband never gave her his phone number. I was there when my husband asked her “how did you get my number?”. She said when he was away, she used his phone to call her phone and that’s how she got my husband number. I know my husband was heart broken when he asked her to stop calling her. Action speaks louder than words. I saw from his expression.
I don’t know if he really falls in love with the girl or the feeling. Their relationship was serious for less than a month. Is that possible that my husband really in love with this girl? I asked him do you love her? He ignored my question and he said just give him time to forget about her. He said he feels shame. He was always a good husband and good daddy. He doesn’t want to talk about it, is it because he feels bad that he only wants to have sexual desire with her and not really love her.
Please, please help me! I really want to know does my husband in love with this girl? Please give me your opinion. Thanks.