Name changed for this, which I originally posted on SEN board but got little response, so I thought I would come on here. Be kind to me please? I am feeling fragile. DD is 20 & dx ASD. She is so-called high functioning, very academically intelligent but socially inept, severe anxiety which she is on medication for. Never had a boy or girlfriend. (DH & I thought she was Asexual) No friends in real life. A couple of weeks ago she dropped a bombshell that she has a boyfriend who she has been talking to for 2 years & is moving out to live with him in central Europe at a place 3 hours drive from the airport. This boy is 17 & lives with his mum, who apparently owns a beauty shop (that DD, who is a MUA, will work in) & 2 or 3 houses & a flat. I can see to her how it all sounds wonderful & we really hope things are as they have been described & she will be happy, but our imaginations are working overtime & we are petrified!
We told DD we need to meet him first & he is coming over TODAY, 
with a return ticket for 4 days later. DD has bought a one-way ticket to go back with him! We are out of our minds with worry! Any ideas? She was staying at her dads house until a couple of days ago as I had insisted she go over & tell him, but she chickened out & eventually told him by text, to which he responded "we will speak tomorrow" but is yet to call her. 
I am furious at his lack of concern! Her younger sister, who also knows the boy, is unimpressed & decided to stay at their dads. I am heartbroken about the whole situation & so so worried for DD. 
Not sure what advice anyone can offer really, given she is technically an adult, (but with a mental age of about 14) & not involved with any services at all.