... Or am I overreacting?
DD turned 18 2 weeks ago. When she was 14, she got into a relationship with her friend, this was early 2019, there wasn't any major issues really, he was nice and respectful, and I got on okay with him. Then a few months later, just before the first lockdown, DD found out that she was pregnant. I was worried as DD was only 15 and BF had turned 15 a few months earlier, and they still would've been in year 11 when the baby was born. So I advised an abortion, which the bf didn't like as he wanted DD to keep it so he could be a good dad to the baby (his dad was abusive towards him so I suppose I do get why he wanted this), DD sadly had a miscarriage and after this he seemed to change, he got involved in drugs, and drinking and seemed to go off the rails so I told him he wasn't welcome around here. They broke up not long after as he told DD he cheated after an argument, he later denied it and said he just wanted to upset her.
They then got back together early last year and they were together for about 3/4 months, the whole relationship I said he wasn't welcome around here and they then split up again due to the arguments. He blocked DD a few months later as he got into a new relationship.
A few months ago, he unblocked her and sent her a very long message apologising, I advised DD to ignore so she did. He messaged again and DD replied and he told DD he wanted to be friends, so DD agreed. Yesterday, they went out together and she brought him back here, later on I told her that he still isn't welcome, DD argued and said he has changed, apparently he's being diagnosed with autism which is the reason for his previous behaviour and she said I should understand as my youngest DS(5) is autistic.
Am I BU? WWYD?