well, this has happened to an ex work colleague, she went to texas in january supposedly for a 2 week holiday with a bloke she had met online, she overstayed (apparently never even booked a return flight which i thought was illegal) anyway, they married at the end of feb in texas, again, how legal the marriage was i don;t know, then in august he cheated on here and she had to come home but had no valid visa to be there and was terrified of being jailed as an illegal, the british embassy helped her but it took a month and alot of money to get her back, her sister had to go and get her. at the airport she was interviewed and had that stamped on her paperwork. she's now jobless and living with family and trying to get a divorce. nightmare.