Aunt to Lover

I'm Robert 25 work as a mechanic and am buying my own 3 bedroom home, I moved to the state capital late 2020 to work for a large trucking company. Found a house at a good price and bought it. But I've been renovating it and fixing its problems since moving in. My father as 3 younger siblings and Erica 35 is the youngest and also lives in this city. Not that I have had much to do with her over the years. Growing up I heard her referred to as strange and weird. In March 2021 I heard from my father, Erica was in trouble and needed a place to live till her life got back on track. He asked would I mind having his sister stay with me. I said no problem she is welcome to stay with me, with a little uneasiness in my acceptance. It was a Thursday and on the Saturday morning an old car pulled into my driveway and a woman dressed in black got out and came to my door. It was Erica and she had black lipstick, eye shadow and skull earrings on to complete her Elvira look. Her dress wasn't figure hugging like Elvira's dresses, but did show a lot of cleavage. Anyway I showed her to her room and helped unload her things and while she settled in I gave her car an overdue servicing. She wasn't talkative and kept to herself mostly, would go out to do whatever she did and offered to pay me for letting her stay with me. I said no as you do the cooking and I think that's payment enough, I'm saying lots on take outs. I'm not big on the dating scene, mainly I'm not seen on the dating scene. I don't do well with girls and so spend my time doing my house. Erica noticed my lack of a social life, but didn't ask or try to get me to change my behavior. But after several months living together we were getting on very well indeed. My birthday came up last July and my parents Robert and Sylvia and sister Sally came a for quick visit help me becoming 25. We all went out to dinner and had a great time, including Erica. My parents and sister returned home the next day Sunday before lunchtime. I was sitting fixing an old cabinet door lock and Erica came to me and said she had my birthday present. I said you didn't have too, she said I really want too. She opened the black robe was wearing showing me her fantastic nude body. I was in shock and and excited at the same time, she took my hand and led me to my bed. We fucked several times and after that afternoon it became a regular thing for us to do. Erica told me sex is sex and it doesn't matter who you have it with as long as it consensual. I'm quite happy with that and we now share the same bed every night, mainly because of a mishap in early January. We had a little too much to drink and had sex without taking any precautions and Erica got pregnant. Much to the amusement of my sister Sally and it annoyed Robert and Sylvia. But as all test showed the baby is healthy they have started looking forward their first grandchild. They know I'm still fucking Erica, as on their last visit we shared the same bed Erica and me. Other family members have also come around.